Blinking Maps on Travel stone and World Map

I observed this yesterday when grotto map was blinking on the World map as well as on travel stone too.
I went to grotto and cleared the entire map, opened every chest. Nothing special.
Later went to watery grave and saw the PW map and grotto was blinking there as well. I cleared the PW Grotto too and found nothing special (though I got 2 legendaries).
Found nothing special in both normal world map and on the PW map. Was expecting a unique drop assuming this to be a secret feature DSO would announce later, was too Optimistic about DSO

This is the third time I see a map blinking on the world map.
I have no quest at grotto therefore it is no quest guidance notification.
The blinking lasted for a day.
So is it just a Bug or has it got some hidden reason?

You can see grotto blinking unusually on the world map and on the PW map as well

 

I think it's because you have an active quest in Grotto. noticed the map area where I had a currently active quest(The quest that gets minimised on the left side of the screen).

 

you have quest guidance activated on a quest which has to be done in grotto.

 

I shall quote myself again

Edit: If it was a quest guidance notification, then there has to be the directions on ground heading towards the door to Jarlshofn. You can see no such directions in the video and still the grotto map blinks, so this is not about any quest.

 

You have quest guidance active for it on one of your other characters.

 

This could be just like when I exit a group I get qued for a 3v3... Never can stop that lol...