trying to sign into BT email using Firefix fails with invalid username or password. If I use Edge then I can log into the email OK. This worked yesterday OK. If I use Edge, then I can get into BT email OK, so the password isn't wrong, and a BT support person said that they've had a lot of people recently failing to get into email if they use Firefox, but other browsers are OK. I can't see this issue reported elsewhere, other than several years ago. Help...