Yes I do find the code lines you posted in includes/login.inc.php

I have automatic login enabled in the admin advanced settings. This problem happens with all user accounts whether they have automatic login ticked or not ticked within their user settings.

Within the admin advanced serttings
If I put 0 in the box failed login is disabled
If I put 1 in the box failed login works for 1 minute

If I put any other number in the box failed login does not block.

Could I try replacing the includes/login.inc.php file with the includes/login.inc.php from the 2.3.7 folder again