Changes Last 72 Hours After Addon Domain is Installed

I am installing the addon domain to go to the same domain. However, I also set up the addon domain as a subdomain. So as an example
Main site:
addon domain:

and it points to the same root i.e. public_html

No problem so far. However, after this addon domain installation is completed, any changes I make are immediately reflected in the main domain, while they are reflected in the addon domain after 72 hours.

In my attempts, the domains were redirected to NameCheap but to Cloudflare. All cache is cleared via Cloudflare, TTL time is reduced. The subdomain set as the addon domain was deleted and re-added. All Litespeed cache has been cleared. The addon domain was completely deleted via cyberpanel and reinstalled with the same name.
Synchronous and changed files with the master were scanned through the addon domain cyberpanel.

In addition, access permission was given to the addon domain, css, image formats, file formats… via the openlitespeed web panel.

VDS server restart, 4 option restart on cyberpanel, graceful restart via openlitespeed methods were tried.

None of these ways solved the problem. How can I solve this problem? I do not want to share the domain openly here, but I think I have explained the problem in detail. Thanks.