B450 pro4 IO errors on external HDDs

I would recommend updating your chipset/all in one drivers. I find that most often
windows updates break things then AMD releases a new driver package to fix them
again.

And these drives worked without error prior to the windows update? More often than
not, IO errors on external drives come down to either bad cables or bad drives.
If you have ruled out the drives then the next thing to rule out is the cables.

External HDDs are incredibly sensitive to cable length and voltage drop. We had
another forum member complaining about similar issues a few months back. In the
end it turned out that they had replaced their case and were trying to use the
front panel USB ports to connect their drives. It had worked fine in the old case
because the front panel headers used short cables to connect to the motherboard
but the new case used much longer cables and it was causing too much voltage droop.
We were back and forth troubleshooting for quite some time before figuring it out.

Try the drives connected to rear IO USB ports using shorter cables and see if that
clears it up.

If not then try a live linux distro on a USB drive and see if you get errors under
linux to rule out the windows update itself as being the issue. You will likely
need to use a linux drive testing tool.