Just wanted to share here, in case someone else faced the same issues as me. Realised that there is no need to use a Raspberry Pi 4 environment for Docker, within Raspberry Pi 4 itself. It is Docker, so swapped to Debian Buster, for arm-based system instead, and the problem is solved.
https://hub.docker.com/layers/library/debian/buster/images/sha256-a067a9e8b39d5f19659b3bc9fd4348f6319afabd0d6ba1fe3b43df108926ea92?context=explore
toughpine got a reaction from JColvin in [Solved] Runtime fails to setup in Docker
