@Tony Thank you for the response! I have one drive as HFS+ and the onther is APFS. It looks like they should be writeable based on the chart. This is a separate issue, but I tried to use a third...

I have a AC4000 MU-MIMO Tri Band Router that has two USB hard drives connected to it. I'm running Mac OS 10.15.4 (Catalina). I mounted the drives on my mac via the smb address and I can see them in...