External drives remounting randomly and losing docker mount

I am on a clean setup of LE 10.0.3: (LibreELEC-RPi4.arm-10.0.3.img.gz) on RPi 4 2GB. Over it I installed LinuxServer Portainer(as a docker container) through the add-ons UI. Through this Portainer service UI, I created a few containers and stacks.

I also have 2 external 3.0 HDDs(500GB, 1TB) connected to the RPi, which are mounted/shared in the docker containers. Everything works fine initially, but over a longer run(>12 hrs), the HDD "I think" are being remounted. The mount points would change for an NTFS drive so I reformatted the drive as ext4. Since then the mount points have been consistent. But now when such remounts happen, it causes the docker container to see empty mounts until the containers are restarted. Outside the containers, I can explore the external drives without any difficulty.

Is there a way to find whats happening? Or is there a way to prevent such remounts. Is this a known issue?

Power Supply: 5.1v 3A

PS: Is this the right sub forum? If not please let me know the appropriate one.

TIA

chewitt You were right. This is most probably due to a power issue. When I plug a single hdd it just works but when 2 are attached, I get the occasional remounting issue.

I thought that a 3A power supply would be enough but apparently not. Or maybe the power supply just says 3.0A but doesn't actually provide it.