Funny I was looking into this yesterday.
The ASI120mm is the one with the issue, the bigger unit not the mini, and not the 120mm-s which is the USB3 version.
However I do see reports of issues with this camera ASI120mm mini, but not like the other one. I do have issues with this camera ASI120mm mini in Windows using APT and the native drivers. I had to connect my main camera first 294mc to APT and then connect the ASI120mm mini to PHD2 with the native driver, and always connect the usb cables/hub the exact same way. It's still iffy and that's one of the reasons I recently switched to Pi4.
I am using the 120mm mini mono AND a 294MC on the Raspberry Pi4 and Kstars/Ekos. I had some camera drop outs in PHD2 and couldn't work it out with this configuration. I selected INDI camera and INDI mount in PHD2. At that point you don't start your camera, you just always keep PHD2 running and Ekos will handle that as long as you select PHD2 as the guiding program when you create your Ekos profile. Here:
So I tried the internal guider and was getting good results with no drop outs. Some things to try too:
Here are some things to try regarding this camera (120mm mini mono):
plug it into the hub of your main camera (if that's an option)
plug it directly into a different USB port on your computer, preferably USB2
take it off of the usb3 hub.