Can confirm, was victim of this.

Couldn't figure out why my 5-disk USB enclosure was so ungodly slow. Quickly I saw that it was capping suspiciously close to some ~40MB/s constant, so 480Mbps.

lsusb -v confirmed. As it happened I did some maintenance and had to unplug the whole bay.

Since the port was nearly tucked against a wall I had to find the port by touch and insert somewhat slowly in steps (brush finger/cable tip to find port, insert tip at an angle, set straight, push in) but once in place it was easy to unplug and insert fast...

This was driving me "vanilla ice cream breaks car" nuts...