Regarding updated Arma 3 Server container:
Updated the container this morning, and my server started to Segmentation Fault when starting up.
After a while, noticed that the container was trying to run arma3server_x64. I recalled that it had been running the x32 version before.
So I renamed the x64.exe file to something else, added x64 to the normal arma3server.exe, and everything is now back and running.