I think I'm going to abandon Redhat and go Ubuntu. I don't want to be paddling upstream with one-off problems due to the OS I chose.
I've stood up a Ubuntu 24.04.1server and so far so good. After changing ownership to my directory to www-data, no issues.
I'll keep my RHEL server and this thread open to see if we can get to the bottom of this. I'll post soon after I perform OFN's last suggestion.

Try using apache2 php8.0 module to see if that works:

sudo a2disconf php8.0-fpm
sudo a2enmod php8.0
sudo a2dismod mpm_event
sudo a2dismod fcgid
sudo a2dismod proxy_fcgi
sudo a2enmod mpm_prefork

Modify virtual server and rem out all php8.0-fpm support

sudo systemctl stop php8.0-fpm
sudo systemctl disable php8.0-fpm
sudo systemctl restart apache2

If this does the trick then you've definitely narrowed it down to a php8.0-fpm config issue.

Yes, user and group is apache in php-fpm.d/www.conf

Does the www.conf for php-fpm reflect apache as user and group?

PHP 8.0.30 with php-fpm

On apache2 are you using mod php8,3 or php8.3-fpm? (if not what version of PHP is your RHEL server running)

Also curious if this may work for you: sudo chown -R apache:apache /var/www/

verifyperms.php comes back with positive results:

My webserver is running under the user apache (default for RHEL)

id apache
uid=48(apache) gid=48(apache) groups=48(apache)

https://realgenx.onprem.radiogenx.com/verifyperms.php
The owner-id of your webserver process is: 48
....
Scanning: /var/www/html/realgenx
No permission problems found.

https://realgenx.onprem.radiogenx.com/verifyperms.php?path=../rgx_community_data
The owner-id of your webserver process is: 48
....
Scanning: /var/www/html/rgxcommunitydata
No permission problems found.

I still feel like the validation page is unhappy that the webserver is running under the id apache and not www-data. Wondering if www-data is hardcoded into a config file somewhere?

There's a llttle utility named verifyperms.php which comes bundled with the
System Info component to assist you solving issues like that

Good suggestion OFN but that search didn't return anything. It looks like the process name is httpd and the user is apache. here are a few httpd running as root though.

ps aux | grep httpd
root 49649 0.0 0.3 22096 14996 ? Ss 10:52 0:00 /usr/sbin/httpd -DFOREGROUND
apache 49650 0.0 0.1 23972 7848 ? S 10:52 0:00 /usr/sbin/httpd -DFOREGROUND
apache 49651 0.0 0.3 1573280 14152 ? Sl 10:52 0:02 /usr/sbin/httpd -DFOREGROUND
apache 49652 0.0 0.3 1442144 15832 ? Sl 10:52 0:01 /usr/sbin/httpd -DFOREGROUND
apache 49653 0.0 0.3 1442144 16052 ? Sl 10:52 0:01 /usr/sbin/httpd -DFOREGROUND
apache 49830 0.0 0.3 1442144 15076 ? Sl 10:52 0:01 /usr/sbin/httpd -DFOREGROUND
root 50399 0.0 0.0 221796 2304 pts/0 S+ 17:12 0:00 grep --color=auto httpd

Believe apache2 default user on RHEL is httpd. What does ps aux | grep apache2 say?