Possibly bandwidth overpopulation on the hub ?, try splitting/moving different devices between usb 2/3 hubs.
If any of the devices are only usb2 spec, there's no gain plugging into usb3.
My PC- Ryzen 5 5600x, B550 aorus pro ac, Hyper 212 black, 2 x 16gb F4-3600c16dgtzn kit, NM790 2TB, Nitro+RX6900XT, RM850, Win.10 Pro., LC27G55T.