Magic Mouse does not work with two SSDs attached to iMac

I would like to have two Samsung T5 SSDs attached via USB 3 to my iMac late 2014. If I plug them in while the iMac is running, everything works fine. If I start up the iMac however with both SSDs attached, the Magic Mouse will not work. I then have to unplug the SSDs and restart the computer. Very strange. Does anyone have an idea how to solve this?

It is probably the USB3 devices interfering with bluetooth.

This site explains it very well, and seems to offer some troubleshooting tips as well


Thanks. I will try…

I read the article and I don’t think it describes the problem I have.

Here is what I could find out as far as troubleshooting goes:

Either one of the SSDs plugged in on startup: no problem.

No SSD plugged in on startup and subsequently both SDDs plugged in when iMac is running: no problem.

Both SSDs plugged in on startup: mouse will NOT work. If I now unplug one or both SSDs while the iMac is running in this case, the mouse will still not work until I do a reboot.

That should negate the thesis with the interference with bluetooth, right?

Any further recommendations? The mouse is and continues to stay completely unresponsive when two SSDs are connected on startup.