M1 iMac with two external display issues
 

Well, My display link works but..... It is causing havoc with my external hard drives. My Time Machine drive and other external storage devices. They are connected directly to my iMac. I'm constantly getting "drive not ejected properly" errors when my iMac goes into sleep mode. I see the errors when I wake my machine.
Another issue I have is, if I have a browser window open on my iMac screen with multiple tabs and drag one of the tabs to another connected display its refresh rate drops to an unusable rate. I have to move the entire web browser session to the other display which kinda defeats the purpose of having multiple external displays.
Anyone else experiencing these issues?

What dock are you using..? and length of cables

Plugable 4K Laptop Docking Station Dual Monitor with HDMI or DisplayPort - 12-in-1 Laptop Dock for USB-C or USB 3.0

Cables are all under 3'

If you have not done so already, I would suggest reaching out to Plugable directly for assistance --> https://plugable.com/pages/support