Looks weird, 500 is already way too much, please set it back or to a small number, and try to set 0 to both procSoftLimit and procHardLimit. If it does not work, please submit the issue to email@example.com with this forum post link appended so we can have a further look.
Check the Set up Virtual Host-Level Cache Settings part on https://openlitespeed.org/kb/openlitespeed-cache-module/ page.
Similar case and solution for you https://github.com/usmannasir/cyberpanel/issues/557
LiteSpeed repo does not support 23.04, not sure how you install it.
That message may be due to you did not config the OpenLiteSpeed Listener or VH mapping.
If you have Ubuntu 22.04, please try the script method which...
Please try to upgrade OLS to version v1.7.18, then empty the Memory Soft Limit (bytes), Memory Hard Limit (bytes), Process Soft Limit, and Process Hard Limit value from the web admin > External App > PHP version you are using. Then test it again and let us know if it works.