Given "other recommendations" can mean a lot of things performed or not — do you see any change if you open the page in a Private Window, or start Firefox into Troubleshooting Mode? Do changes in Enhanced Tracking Protection have any impact? (The site looks like it's heavily loading scripts from third parties…) Disabling Bitdefender for a while to verify? (Not sure what "checked with" means in this context.) If you're so inclined, you can try inspecting the page https://firefox-source-docs.mozilla.org/devtools-user/ to see if there's errors in the Network pane, or any red errors directly visible in the Console. That could point to external providers that are stuck/hanging.