Collaborada

You can use the full URL for the destination and you won't see the protocol downgrade. 

Three possibilities come to mind.
A failure on SEMrush's end and they are misreporting the issue.
A failure on Squarespace's end at the time SEMrush crawled your site.
Squarespace is blocking access by SEMrush to some pages of your site. HTTP 403.

@Collaborada - I get where you are coming from now ...
Settings > Marketing > SEO Appearance > Half way down page SEO Appearance: HOME PAGE ITEMS - changed from %p to %I and it worked....
Many thanks

@Samdidam Based on your screenshots above the question looks to be about the meta description.
Currently the description is set to "Erste Schritte mit KI - aiolo unterstützt KMU in der Schweiz, Einsatzmöglichkeiten für KI zu finden und umzusetzen."
Your screenshot of Google SERP shows the site's nav/address, but what I see displayed in Google is: "Wandel von externen Inhalten wie Newsletter, YouTube Videos und Blogs zu Text- und Bild-Content für mehrere Kanäle." This text is found on the Homepage. 

Google likely crawled the page before you'd written a description. Tighten up the meta if needed and ask Google to re-crawl the page.
See Google's help info regarding meta descriptions: "Google will sometimes use the <meta name="description"> tag from a page to generate a snippet in search results, if we think it gives users a more accurate description than would be possible purely from the on-page content."

@Collaborada Again, thank you for this, I'm diving in as we speak.

Hi @EventPlanner the Squarespace panel only displays your top 200 queries with all other queries aggregated into the result labeled “other.” For better detail view your data in Google Search Console. 
 

Thanks so much @Collaborada - I really appreciate your feedback!

The reply above might mislead or confuse beginners:
The length of a meta description is not limited to 150-160 characters. Shorter or sometimes longer descriptions can be appropriate. Google's documentation currently states: "There's no limit on how long a meta description can be, but the snippet is truncated in Google Search results as needed, typically to fit the device width." It is important to understand that including the “main keyword you want to rank for” has no impact on page ranking. The URL Inspection Tool is meant for checking individual page status, not for routine checks of “all URLs.” And requesting indexing does not guarantee quick updates in search results or “refreshed data.” For up-to-date info refer to Google documentation:
Page descriptions: https://developers.google.com/search/docs/appearance/snippet URL inspection tool: https://support.google.com/webmasters/answer/9012289

Hi @blackstarNL you'll also want to refer to Google's documentation on site moves/migrations: https://developers.google.com/search/docs/crawling-indexing/site-move-with-url-changes

It's simple enough, purchase your new domain through Squarspace, and make it your primary one, and leave your existing domain as is. 
Using multiple domains connected to the same site.

Hi @AnnaB12. Make sure to do 301 redirects pointing old content to new content. For example, /seed-management is indexed, but is a 404 on the new site. Keep an eye on Google Search Console. 
Google's documentation on site moves: https://developers.google.com/search/docs/crawling-indexing/site-move-with-url-changes

The reply above might mislead or confuse beginners:
The length of a meta description is not limited to 150-160 characters. Shorter or sometimes longer descriptions can be appropriate. Google's documentation currently states: "There's no limit on how long a meta description can be, but the snippet is truncated in Google Search results as needed, typically to fit the device width." It is important to understand that including the “main keyword you want to rank for” has no impact on page ranking. The URL Inspection Tool is meant for checking individual page status, not for routine checks of “all URLs.” And requesting indexing does not guarantee quick updates in search results or “refreshed data.” For up-to-date info refer to Google documentation:
Page descriptions: https://developers.google.com/search/docs/appearance/snippet URL inspection tool: https://support.google.com/webmasters/answer/9012289

The reply above might mislead or confuse beginners:
The length of a meta description is not limited to 150-160 characters. Shorter or sometimes longer descriptions can be appropriate. Google's documentation currently states: "There's no limit on how long a meta description can be, but the snippet is truncated in Google Search results as needed, typically to fit the device width." It is important to understand that including the “main keyword you want to rank for” has no impact on page ranking. The URL Inspection Tool is meant for checking individual page status, not for routine checks of “all URLs.” And requesting indexing does not guarantee quick updates in search results or “refreshed data.” For up-to-date info refer to Google documentation:
Page descriptions: https://developers.google.com/search/docs/appearance/snippet URL inspection tool: https://support.google.com/webmasters/answer/9012289

YES! Man, wish I'd asked here before burning through hours of ineptitude. Thanks Collaborada, I'm really grateful. 
 

Thanks. This really worked for me by just replacing the "amazon.com" and "amzn.to" part with "https://" and "www." 👍🏼

Hi there. Yes, you need to adjust it for your needs.

You only need to submit this sitemap: https://www.juliapylak.com/sitemap.xml

I wouldn't worry about it. The search engines will drop it eventually, there is nothing you can do right now since the link doesn't go anywhere. Renaming a page is one thing but the main domain change which happens with websites a lot confuses the engines for a while. I would be more concerned about my main domain and you can check for any broken link here:
https://ahrefs.com/broken-link-checker

Thank you!  That solved the issue.  Note, however, that Squarespace has now changed the location to find the custom CSS panel.  You can now find it here: website -->  pages  -->  utilities  -->  website tools  -->  custom CSS.  Why did they need to change the location????

Hi @Kfed. This looks to be a recent migration, so give it some time. Likely by the time you finish the migration work, the favicon issue will sort itself out.

Google does not use the TITLE tag to show the listings in Google like it did before. This is something that has been going on, from memory about 18 months now. If you read Googles Webmasters blog you will find a post detailing this. Do not expect to be able to define what comes out in the SERPS. This change is most likely driven to give more visibility stand-out appearance to the Advertising blocks on the page, where keywords are inserted.
Meta description: very difficult. Generally and historically Google would sniff a page for the keyword in the user's search query and then show a text snippet around that text. This happens to a lesser extent now. Microsoft used to be very good at using the meta-description.
Meta-description length does not have to be within the realms of 150-160 characters long because, there is no direct correlation between the listing and the meta-description because of previous paragraph. The 150-160 character rule was set because it was the length of the available space in a Google underneath the SERPS.  It really had very little to do with SEO as a ranking mechanism, but it was easy and so most tools recommended this for that purpose.
Therefore you can quite happily ignore this constraint knowing that at least you have more words you can insert into a meta-description to have at least keyword presence and the ability to have some kind of control over it, instead of Google sniffing your page and randomly pulling out text it thinks will support the search query.
Good luck.
 
 
 
 
 

The first words on the Home page are: "NOTRE SITE EST ACTUELLEMENT EN CONSTRUCTION. CERTAINES PAGES RISQUENT DE NE PAS S’AFFICHER CORRECTEMENT." 
Translates to: "OUR SITE IS CURRENTLY UNDER CONSTRUCTION. SOME PAGES MAY NOT BE DISPLAYED CORRECTLY." 
You just need to finish the site, remove this statement, then ask for a crawl. 

The first words on the Home page are: "NOTRE SITE EST ACTUELLEMENT EN CONSTRUCTION. CERTAINES PAGES RISQUENT DE NE PAS S’AFFICHER CORRECTEMENT." 
Translates to: "OUR SITE IS CURRENTLY UNDER CONSTRUCTION. SOME PAGES MAY NOT BE DISPLAYED CORRECTLY." 
You just need to finish the site, remove this statement, then ask for a crawl. 

The site has not been indexed (site:ash-architectes.com), and as a result it won't appear in search results. See Google's documentation: https://support.google.com/webmasters/answer/7474347

@Collaborada this was what I was thinking and told them as well but I wanted to see what others thought about it. The SEO person is more in the content side of things and doesn't know much about the technical side and SEM Rush report looked kind of scary to them I think.
 
Thanks!