CWP doesn't control that part.
If you where trying to modify the CWP user login script, then maybe an update did something.
This sounds like a file permissions issue or something with your php.ini
And is a problem between AL8, AL9 and AL10.
All those OS'es handle system security differently. Which is a royal pain in the ...
So security settings on AL8, won't act or even work on AL, and setting from AL8 or AL9 won't act or work on AL10.
This is one problem why some control panels act or do not work at all.
Was behind the Migration problem between AL8 and AL9.
I'm guessing no one bothered testing AL9 before migrating.
But if it works on AL8 with CWP 1.18, and doesn't work on AL9 with the same CWP 1.18, that rules out CWP.
As mentioned above, I would start looking into permissions (users, assigned groups, how is SELinux configured, etc, etc)
I'm not sure why RHEL did this, and hence clones.
It's a pain.
RHEL 8 and clones act similar to CentOS 7.
Another reason CWP needs to drop support for the EOL CentOS 7 and try & focus on AL9 and maybe AL10.