Unraid 6.9.2 - Docker container of specific name keeps stopping

I really hope someone can help me as this is very strange

I had a sonarr docker container which was working fine, but then suddenly would only run for 5 minutes without stopping.

I don't think that sonarr itself is actually the issue though. It seems to be the name of the container, not what is in it.

My original container was called "sonarr". I recreated an identical copy of the container with a different name - "sonarr2" - and it ran for several hours. I then stopped the container, deleted the old "sonarr" container and renamed the new one to "sonarr". The container stopped after ~5 minutes. I changed it to "sonarr2" again and it ran for several hours again. I repeated this name change several times with the same result - "sonarr" stops, "sonarr2" never stopped. It has now been running as sonarr2 for 20 hours. 

What can possibly have happened? Can I somehow "clear" the seemingly wonky "sonarr" name so I can use it again?

This is a chunk of server logs from when I was renaming containers
https://pastebin.com/DYajFwp8 

This is my Docker run command

root@localhost:# /usr/local/emhttp/plugins/dynamix.docker.manager/scripts/docker create --name='sonarr2' --net='bridge' -e TZ="Europe/London" -e HOST_OS="Unraid" -e 'PUID'='99' -e 'PGID'='100' -p '8989:8989/tcp' -v '/dev/rtc':'/dev/rtc':'ro' -v '/mnt/user/Videos/':'/tv':'rw' -v '/mnt/user/Downloads/':'/downloads':'rw' -v '/mnt/user/mount_rclone/dropbox/To Mum & Dad/':'/export':'rw' -v '/mnt/user/Downloads/Scripts/':'/scripts':'rw' -v '/mnt/user/appdata/sonarr':'/config':'rw' --security-opt seccomp=unconfined 'linuxserver/sonarr'
704bcfa29e947831767a7c3970cd6591abfe529faa326049f7fbd7cf4c176f37

I have been told on the sonarr forum that there is nothing amiss in the sonarr logs - they just stop logging when the container stops, but these are some debug logs from a stopping incident
https://pastebin.com/16Xb15FV