FP 4 app lounge not working v1.2

You should definitely Clear Storage as well as Cache.

Also I think worth experimenting does it make a difference using only mobile data or only Wi-Fi.

There is this troubleshooting guide. Sometimes it might need cycling through the steps so that you are able to sign T&C.

Edit, repair link.

https://doc.e.foundation/support-topics/app_lounge_troubleshooting.html

Also try avoid European peak / weekend times.