I have a USB2 GPS dongle and some USB3 kit (mem stick, ASI120MC) to hook up to my Stellarmate RPI4 (with RTC). It’s well documented that USB3.0 and GPS don’t work well together and I can see that happening when I plug in a USB3 device and the USB dongle stops communicating its position. Now, the ‘static’ solution would be to prevent all USB3 devices from interfering by plugging them into USB2 ports, but that of course brings the speed down. Question is: is it ok to unplug the USB dongle once kstars is started, Ekos is started and the GPS info has been synced to all devices? Thanks for your help.

I plug a USB2 GPS dongle into a USB3 front panel socket on my Beelink GK55 running Ubuntu (not SM but still linux) and have no problems with speed or stability.
I do have a lot of stability issues if I plug or unplug it when Linux is running though.

Thanks for your respons Damian. Do you have any other USB3 devices plugged in? I see you have some ZWO cameras, are they USB3?

Hi Tom
Yes I have 2x ZWO USB 3 cameras plugged in and there's a USB3 type C socket in use which goes to a 4 port USB3 hub and has more connected there (HEQ5 / ZWO EAF - both USB2 etc) .
I can't use the rear USB2 ports as they interfere with the mount when it rotates, so I have to extend the USB3 Type C with the hub and use that.
I have had issues with cheaper USB hubs in the past but this powered one has been solid.