OpenLightspeed is a free and opensource variant of the commercially available Litespeed. Both are (unlike Nginx) a drop in replacement for Apache and both can read the Apache configuration files including .htaccess files.

The crucial difference is that the commercial version can update itself when a change is made to these files, while OpenLitespeed can not update itself after such changes, you have to restart the litespeed server before the changes are reflected.

This means that OpenLitespeed is not really suitable for running a hosting business as each time a client makes a chenge to a configuration file they would need to ask you to restart the server. Of course the enterprise edition is more suited to the hosting environment as these changes are reflected automatically just like with apache but with the added speed advantage of Litespeed.

OpenLitespeed therefore is more suited to the person who is hosting his own websites on a VPS or other server and is quite happy to restart Litespeed after making changes.

Openlitespeed is more or less the same as the commercial version apart from the .htaccess issue.

I do not believe that your problem is litespeed related but more to do with the aapanel litespeed plugin, which incomplete to say the least. eg it does not have the webmin control panel to fine tune it like you do with cyberpanel or OL installed directly on a server.

Have you been on the aapanel forum to say what they are saying about it?

https://forum.aapanel.com/

Yes it is available with cyberpanel or OL installed direct but not unfortunately with aapanel plugin.

See here. https://openlitespeed.org/kb/ols-web-admin-console/

I take it you rebuilt PHP after installing OL as it is different to apache PHP?