Console window keeps popping up

Did some further investigation and considering the fact the first time I've noticed, Office Click to Run was active, I have the suspicion that this is indeed the issue also described here on Reddit:

Yesterday I noticed something weird at my Desktop PC, CMD popped up with an hour between, exactly, but it disappeared again too fast for me to have any chance of seeing what the title is, or if there's any text, or anything, in fact I'm not 100% sure it's CMD, but it has the shape and color. I thought this was a specific program doing it, so I went through the event viewer, unable to find anything, but just gave up there.

Today on my Laptop, an hour after turning it on, the excact same thing happened to me, though Chrome and Spotify were running on both PC's I believe it has something to do with Windows... If anyone knows anything about it, please help, because it's annoying as hell to be tabbed out of your game, or concentration because of such a little thing.

So it seems several Reddit users noticed the same problem and they've come to a similar conlusion as me:

I went to the Task Scheduler > Task Scheduler Library > Microsoft > Office and found and disabled "OfficeBackgroundTaskHandlerRegistration"

So I checked my Scheduled Tasks, opened the Microsoft and Office categories and indeed the OfficeBackgroundTaskHandlerRegistration task ran the exact moment I've noticed the popup the last time.

Running the task by hand led to the exact same result: a console window popping up for a split second.

So guess Microsoft changed something in the program ran for this task. You can probably disable the task for now, although I don't know whether there's any impact on doing so.

SOLUTION: Run Task Scheduler > Microsoft > Office > Right click "OfficeBackgroundTaskHandlerRegistration" > Disable.

Here's an image of the location I created in case you need extra help: