Microsoft Edge keeps closing down

In my favourites bar in Edge I have more favourites folders than there is space for across the screen so there is a down arrow on the right. When I click on this down arrow the remaining favourites folders appear. If I launch Edge, click on the down arrow and select one of these remaining folders, Edge closes down. However, if I launch Edge and select one of the folders in the favourites bar across the top of the screen this doesn't happen. And once I've selected one of these folders in the favourites bar across the top of the screen I can then click the down arrow and select one of these favourites and Edge does not close down. Can anyone suggest what I can do to put this right, please?

And one other thing, every so often Edge starts flashing on and off. I wonder if that's connected with the above problem.

Thanks. The flashing has stopped now but I'll try your suggestion if it starts again. Still got the problem with Edge closing down, though.