Reproduction steps:
1. Open the “MinUVC" project
2. Click “Login or sign up” in the “Unity Version Control” window (you should become signed in)
3. Dock the “Sign in to Unity VCS” window
4. Reopen the project
5. Try to sign in with Email in the “Sign in to Unity VCS“ window

Expected result: It’s clear that the user is already signed
Actual result: A confusing “unexpected error has occurred” Unity Version Control error pops up

6. Try to sign in with Unity ID in the "Sign in to Unity VCS" window

Expected result: It’s clear that the user is already signed
Actual result: Infinitely "waiting for a session"

Reproduced in: 2.0.5 (2021.3.27f1, 2022.3.2f1, 2023.1.0f1, 2023.2.0a19), 2.1.0-preview.6 (2023.2.0a19)

Reproduced using: Windows 11 (by the reporter), macOS 13.4 (Intel)

Note: Also reproduced when removing an account using the PlasticSCM app (see the internal “plastic.mp4” attachment)