Like "GiNGL3like a sir" replied on January 11, 2023:
"Thought it might have been worth mentioning, I had this issue and noticed it could have been my external hard drive intermittently disconnecting and connecting. Through Control Panel > Autoplay > Untick "Use Autoplay for all media and devices" and see if that helps."
I was suspecting this, and pulled out my USB-connected external drive. Then plugged it in again, and Explorer popped to the front.
So an external drive disconnecting/reconnecting randomly combined with the setting "Use AutoPlay for all media and devices" active is definitaly the culprit here.
For "Removeable drive" I had the setting set to "Open folder to view files (File Explorer)".
Turned off "Use AutoPlay for all media and devices" and it solved the problem. Why would you ever want the OS do something automatically when plugging in an external storage device, security-wise it is really stupid.
Remove AUTOPLAY!
/rob