I experience the same as @howiser1. Everything works fine with nextcloud on unraid until the iOS app is used to authenticate against the server: nextcloud stops responding (502 in the ios app log), and I can't restart/stop the container on unraid. Even stopping the docker service doesn't resolve, the unraid server itself will not shutdown/restart and needs a hard reset, which is bad.
I can recreate this consistently, so there is definitely an issue here with the unraid/nextcloud/ios combination. It's been a consistent problem for me across all recent versions of nextcloud and unraid.
I do use swag and cloudflare and access nextcloud externally, unsure if this is also playing a part.
Be great to know if anyone has any ideas on why this is happening. @howiser1 I see your post was from last year - do you still experience the issue?