Login fails 50% of the time (User is not logged in.)

[JavidPack]

My site worked before, but I had to re-install the operating system recently. Now, my site logs in about 50% of the time. When it fails, I am met with the familiar "User is not logged in." message. When the login fails, my url bar shows a long url similar to this:
register.php?login&openid.ns=http%3A%2F%2Fspecs.openid.net%2Fauth%2F2.0&openid.mode=id_res&... and so on.

I've looked around at old issues, and the closest issue I could find was #210 , but logging the response_nonce didn't confirm the issue happened reliably with a space in it.

The only thing of note on my end is that much of the hosting software has been updated since my previous iteration of my website:
PHP is now 7.3.9 (using php-fpm instead of php-cgi)
Debian is now 10 instead of 9
lighttpd is now 1.4.53
etc.

Please let me know any additional logging or tests I can do to figure this out, I've poked around the validate method and tried logging various things, but don't quite know what further things to test.

[simas289]

I know this is an old post, but were you maybe using a localhost to run it? For some reason I believe that it might be the problem for me, but I want to get some confirmation from you.

[JavidPack]

No, it's a public site.