Screen Mirroring Icon Dissapearing

[strixton]

Usually when I play a video on my phone at the start bottom right I see the screen mirroring icon which I hit it finds my Samsung TV connects to and all is good.

Just recently the icon shows momentarily then disappears....any idea how to get it back?

 

[strixton]

Re-booted modem which sorted the issue, now connects to TV again through the screen cast icon.