Thanks Morigan. could you tell me where that support tool is found?
I contacted Siteground, and this is how they responded:
This is a custom PHP application.
After further expecting your website I could see that it is requesting CSS files: https://tinyurl.com/y47rwma2
However, these files are not presented inside your folder:
baseos | firstname.lastname@example.org:~/www/supergrowthmultibaggers.com/public_html/forums/uploads/css_built_2$ ll
drwxrwxrwx 2 u654-2hxw2v2nqgxv u654-2hxw2v2nqgxv 4096 Oct 29 23:41 .
drwxr-xr-x 16 u654-2hxw2v2nqgxv u654-2hxw2v2nqgxv 4096 Oct 29 20:53 ..
-rw-rw-rw- 1 u654-2hxw2v2nqgxv u654-2hxw2v2nqgxv 2449 Oct 29 23:41 0f77ccc23699bd2e478540afa0a01bca_messaging.css
-rw-rw-rw- 1 u654-2hxw2v2nqgxv u654-2hxw2v2nqgxv 1487 Oct 29 23:41 865d35a093ea7fe810226fce751a69f9_messaging_responsive.css