Hi, I'm Elise, an independent advisor and I'd be happy to help with your issue.
It appears to be relates to casting the screen to another device.
http://www.dial-multiscreen.org
If you navigate to edge://flags/ then search for 'media router' you should be able to disable the feature if you wish.
Kind Regards,
Elise
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.