Hard drive connected to USB hub disconnects randomly

One of the hard drives I have attached to a USB hub keeps disconnecting randomly but cannot be dismounted because it claims to be being used by an application. The only way to get it to work is to unplug it, wait a minute or two, and then plug it back in. It contains an assortment of music and other large files including a few videos, installers, and audiobooks, and I normally don't notice it's disconnected itself until a Carbon Copy Cloner backup fails. This has been going on a while, and I am trying to figure out where the problem is and what I can do about it.

I am running a 2018 MacMini on Big Sur which does not have enough ports to handle all my external disks and other accessories. I have a printer, a scanner, external speakers, a webcam, a DVD drive (on audio port), external data drive, an external CCC backup drive, an external time machine drive, and need ports for other USB devices including mouse, keyboard, audio headphones, and a digital camera. I have a 7-port powered Orico USB3 Hub plugged into one of the ports in the MacMini, and an unpowered four-port manhattan USB hub plugged into another port on the MacMini. The troublesome external hard drive is a Western Digital MyPassport with 1 terabyte capacity and a little over 200 gigabits stored on it. The data disk is now plugged into the 7-port Orico hub, but it also disconnects when plugged into the four-port hub. All the drivers are spinners except the internal drive on the Mini.

Any idea what might be the problem here? I'm inclined to suspect the hubs, but moving from port to port does not seem to stop the problem. The drive tests OK or is repairable by Disk Utility after it disconnects itself. Is there some better way to connect all the devices to the Mini? (If so- what is it?) Could this be a dust issue; the drives sit on an old computer desk in my attic office, and I have replaced other older hubs when they started getting dusty or cruddy on the outside. The office gets hot in the summer, but this is not just a summertime problem.

Any suggests would be welcome.

Thanks,