Hi for some reason since upgrading to 20.04 my usb ports behave funny.
Any external drive that stays connected works fine.
However any drive un-mounted still leaves the drive listed in Files and any attempt at a later time to connect another drive does not detect the new new drive.
Only way to for the system to recognise the the new drive is to reboot or recently I found that suspending the system and waking it up then 'wakes' up the port again.
I have had my auto suspend disabled in my grub for a few ubuntu versions.
UPDATE: the responses has been great. Useing the safely remove options correctly removes the drive from the files app now, But I still notice I have to suspend the laptop to wake up the USB port again. Even when using the exact same drive I just safely removed.
1 more thing I forgot to mention the usb ports are on a usb hub.