Anker USB C Hub, Aluminum USB C Adapter with 4 USB 3.0 Ports With External HDDs

I am having difficulty using this hub with my 2018 Mac mini and external Hard Disk Drives.

If I plug more than one drive into any one of the three hubs that I have purchased, I get sporadic errors where the drives are going off-line and then immediately coming back on line.

This will happen once or twice a day. In many cases. This sometimes causes the Mac mini to reboot when trying to write to the drive.

I have to unmount the drive and then power it down and then back up to be able to read and write to the drive.

The drives seem to work properly with a powered Hub. No errors.

The external drives all have their own power supply.

The HDDs are Western Digital.

Has anyone else seen this, or have any ideas how I can use the Anker Hubs and still have stability?

Thank you