As this can help someone:
Turns out that the problem is the parameter fs.s3a.endpoint. We’ve been using a DNS adress so far without much problems, but this time, somehow, didn’t work out. Changing it to the IP address solved the problem.
Also, this is a known issue for older versions, but it should have been corrected on 22.1 as can be seem on Dremio fails to start after upgrading to 22.1 - Dremio.