Need your help error http 500

[Dorothy Thin]

Hello guys I have a VPS with whm cpanel and a few customers on it about 3 of my customers using DHRU script they are having HTTP 500 problem some times and it become resolved when they change the PHP version and like to 7.3 and then back to 7.4 or even stay on 7.3 I need to know the solution for this issue any idea??
Thank you already.

[Enzoengine690]

In my opinion, you should double-check your database credentials to ensure that they are correctly assigned.

This is because internal error 500 is caused by your database being unable to be read or by your httpd response time.

You could also try configuring your PHP by editing the php.ini file to increase the RAM load size and response init timer.