For the past couple of months I've had this weird problem. IntelliJ IDEA (IC-201.7846.6) is usually open idle in the background, but from time to time (averages at about once per day) it suddenly grabs focus but doesn't go to top. If I happened to be typing in another application, watching full screen video, or wherever, the keystrokes end up in the file open in IDEA instead of the foreground application, and I have to click the foreground application to re-grab focus. It seems it doesn't happen entirely random as I've seen a couple of times where it occurred after using IDEA and then doing something else for 15~30 minutes when it occurs. It happens on two different computers both running Ubuntu 18.04LTS.
I can't find a bug report but the problem is so vague that I cannot exclude it either. Has anyone else experienced similar things?