Google indexing for the subdomain of the program installation

[maniks]

Hello,
I have a subdomain https://poczta.mczajkowski.pl and until now it has been indexed at this address for many years. After updating the email program, she suddenly disappeared from the search engine.
I did not notice the errors of the updated program, so I started to rummage in the console, but I also did not find the reason.
I added in the console hearts, additionally sitemap.xml pages, and only Google has crawled it and sees after the entry "site" which I'm rather not satisfied with.
The page in index.html has follow and robots.txt file so that the search engine can see it.

The console screen even disappeared, which was previously visible there. And in the item "Status" it appears as an excluded scanned, but not indexed

Is anyone able to tell me what happened and why after a few years the site suddenly disappeared from the search engine?

[rm13]

The page is returning a 401 Unauthorized in the headers. Search engines may choose not to index such a page.

What version of Roundcube are you using? Looks like it may have been changed here:
https://github.com/roundcube/roundcubemail/issues/5663

That said, not sure why you want your login page indexed by search engines. This would make it a somewhat more inviting target to malicious bots.