oAuth Users loose R.C-Role

[OlafDammann]

Description:

R.C uses oAUTH against a WordPress running the Plugin "WP OAuth Server". Logging in works, a new user will be created in R.C.
BUT the User will not have any role AND the manually added role "user" disappears over time (maybe after they login again or after some time passed by).

Steps to reproduce:

1. Install a WordPress and add and configure the Plugin "WP OAuth Server"
2. Connect an R.C-Server via oAuth to it
   3 login usind WP-Users credentials
3. In R.C Users-List you can see the user without a role.

Expected behavior:

The roles shall not disappear. At the moment R.C is heavily unusable.

Actual behavior:

as explained, the roles go away

Server Setup Information:

• Version of Rocket.Chat Server: 370
• Operating System: Ubuntu 18.04.5 LTS
• Deployment Method: your official Docker image on
• Number of Running Instances: 1
• DB Replicaset Oplog:
• NodeJS Version:
• MongoDB Version: 4.0

Client Setup Information

Any client

Additional context

Relevant logs:

[bbrauns]

probably same as #17466

[OlafDammann]

probably same as #17466

Sounds a bit like.
Is maybe deactivating the "merge roles"-option a way? what does it do?