modsquare

The code is not complete, it needs a closing bracket: >
I'm not sure why you can't save after removing it, you probably want to contact Squarespace Support:
https://support.squarespace.com/hc/en-us/requests/new#choose-topic
You could try correcting the code and saving, then removing it and saving. Or if you can't leave it blank, leave it as:
<meta>
In the future you might want to know that you don't need to add this code to hide a page from search results, look in the SEO tab in the page settings, and toggle "hide from search results"

Hello Mak! The code that is injected is fine and isn't overriding the page titles/meta descriptions. That code is called structured markup (or schema) that helps search engines understand specific things, in this case, information about your business.
I did a quick scan of your site and actually the site is set-up and displaying the page title and meta descriptions as you want them. However, what you are seeing is the new way that Google works. They are using artificial intelligence now to re-write page titles and meta descriptions based on what they think the searcher is looking for, rather than what you want them to see. And yes, this is super frustrating when you have a specific way you want it to look and read. So it's nothing you're doing wrong, it's just how Google is now doing things and at the moment there doesn't appear to be many ways around this.
 
Edited for punctuation.