Invalid Security Token” after updating to Grav v1.8.0-beta.4 (Admin v1.10.49)

Hello,

I recently updated to Grav v1.8.0-beta.4 with Admin v1.10.49.
Since the update I keep getting “Invalid Security Token” on the Admin login (see screenshot).

What I tried:

Cleared Grav cache (bin/grav clearcache) and browser cache

File/folder permissions are OK (writable: user/, cache/, logs/, tmp/, images/, assets/, backup/)

Interesting behavior:

I can log in via Chrome Incognito.

After logging out and trying to log in again (normal window), I immediately get “Invalid Security Token” again.

Any ideas what changed in 1.8 beta that could cause this? Is there a session/cookie setting I should

Try clearing cookies and sessions

I did but, didn’t resolve the issue!
Any other solution?!

Did you try all the suggestions provided here?
https://learn.getgrav.org/17/troubleshooting/invalid-security-token