Following a institution-forced mandatory password change I cannot get to login from the macOS client, as the login screen does not display any input fields.
See the attached screenshot.
Login to the server directly in the browser works.
This is with version 2.6.4stable (build 20200303) on macOS Catalina with all updates installed as of today.
To provide some further details: this problem exists with client versions 2.6.3 and 2.6.4 as well as the 2.7.0-beta1.
It does not exist for 2.6.1 and 2.6.2, which thus allow login and synchronization.