[CentOS] USB drive very slow on CentOS 8

I recently upgraded from CentOS 7 to CentOS 8.

I have a Mediasonic HF2-SU3S2 external drive enclosure with 4x3Tb drives configured as a software RAID 5 array (mdadm) with LVM. It's connected to a USB 3.0 port.

On CentOS 7, the drive performance is reasonable. On CentOS 8, performance is extremely slow, about USB 1.0 performance. Maybe worse.

Connecting an external USB SSD to the CentOS 8 system appears to perform well.

I've updated the ASUS Prime-B350-Plus motherboard with the latest BIOS, but it doesn't appear to make any difference.

Does anyone have any idea what might be different between CentOS 7 and 8 that would cause this?