Hey Creedon, I like the way you logically work through issues on this board and so I thought I would come to you with my own version of "grayed out" home page settings.
I am an SEO consultant and have been since 2001. You would think I would know how to get around this stuff...LOL. But in this instance, it is my son's site that has the issue, not mine.
Originally, he (unwittingly) set his home page as /home. But then a couple of months later he changed the URL to just /. This of course created a duplicate content dilemma, with two different URLs pointing to the home page.
I stepped in at this point and did a 301 redirect i.e. /home -> /
On my iPhone, when I check the redirect to see if it is working, it appears to be working fine. But on my laptop, it still allows the two different URLs to bring up the home page. I tested it out on a different computer that had never previously searched for this site... and the redirect didn't work -- it brought up both versions (separately) of the home page URL.
Anyway, that is only ONE of three problems. The second is that /home is showing in the xml sitemap, not /. That is a "NO NO" with Google and so I am hoping that you might have a workaround or a fix for both these issues.
Thirdly, the dreaded "greyed out" home page thing: My son's home page settings are greyed out - for the URL/home (and there is no sign of any alternate home page in the pages area, even though both versions of the home page URL fetch the home page.
The URL Slug show up as Home/ (see below) and the Navigation Title reads Home -- even though I personally reworked the Meta Title to read something quite different (in the SEO section of Squarespace).
Apparently, according to my data on SEMrush, /home is the canonical version (or one of two canonical versions even?). Either way, it should NOT BE the canonical, and I do not know how to fix that because it is my understanding (which is quite likely incorrect) that Squarespace assigns canonicals automatically and/or I don't have access to the snippet of code in the <head>.
The bottom line is that I simply want to remove all traces of /home and only have /.