[mohr01]

"I installed FOSSBilling on a subdomain created and hosted on my server, which uses ISPConfig3 as the control panel. I also found a module on GitHub, 'https://github.com/FOSSBilling/ISPConfig-3,' which I implemented in FOSSBilling according to the instructions, and it is working perfectly. With its help, I was able to create packages, and the client successfully chose a package. My issue is the following: when I try to access https://mydomain.ro/admin and enter the credentials (administrator username and password), it takes a very long time to load the administration page. After it loads, the page runs very smoothly and quickly, but if I log out and try to log in again as an administrator, the same issue occurs — it loads very slowly."

Could you open developer tools->networking in your browser and see if there's any error?

Also have you checked fossbilling logs and any proxy server logs?

Someone is taking more time than expect to answer, maybe..