Unable to login to 1Password 8 beta

I, too, had this problem - but it only recently developed.

I'd been using the 1P8 betas since they came out, but, this week ran into a problem: Anything that I added to 1P8 on my MacPro would not synchronise to anything else. It was showing in 1P8 on the Mac, but, it was not showing up in the 1P website, nor on any of my other devices.

In a (foolish) attempt to fix this, I "signed out" of 1Password on my Mac.

I am now unable to sign back in. I am 100% sure the Master Password is correct, and, like others, I have a YubiKey as well a OTP via Authy on my account.

Ironically, because I could not sign in to this forum, as 1P had my credentials stored (and a working 1P is essential to me), I went ahead and downgraded back to 7.9; everything is working just fine again now, however, several items that I added in 1P8 are now entirely lost to me and I'm unable to access the data, or the services, which I had set up in 1P8 on the Mac.

My fault for using a Beta, I know, but, was trying to give the Electron mess a fair shot. Must say, REALLLLLY prefer 7.9.x again...

Anyway, can't send the diagnostics, as installing 7.9.x seems to have nuked 8.x beta. I'm assuming the many items I've recently added that were not synchronising with your back-end storage are permanently gone.