"Collabora Online" App + external drives + AD Login (LDAP) problem

Hello, our users are all LDAP users coming from a Windows domain. Therefore our users can authenticate via “AD Login”. Then I included two external drives that reside on Windows Server in our network. Our users use the intigrated “Collabora Online” app. When Office files are opened on the local Nextcloud server, everything works very well. However, if Office documents are opened on the two external drives and authentication is set to “session credentials”, the Office documents can not be opened using the “Collabora Online” app. But if I put the “log in to database”, everything works. The problem is that the next morning all AD users have a blocked account in the Dömane. I wonder, before that comes? Is this a mistake? So a work in our constellation is not possible. Thank you.

It does not matter if I work with NC 14.06 or 15.02. I tested both. Both versions behave the same way.

I’m having the exact same issue except the blocked accounts.
We probably have different Domain Security Policies.
Using Nextcloud 15.0.4

Same problem on 15.0.5 RC1
Just get a spinning circle in the middle of the page.

Same issue with 15.0.5. All add-ons and CODE server up to date. Our NC and CODE servers are both running on Ubuntu 18.04.01
Find any solutions yet?

Same with 21beta, two years later. Any solutions for this?