I purchased a 4k firestick a few months ago and at first, I had no issue with casting straight from my phone on YouTube to the TV. I'm not sure what happened but my phone just stopped being able to recognise the stick over wifi despite having no problems doing so with the roku downstairs. I now to have connect to YouTube by using a code on my phone. I replaced the roku downstairs with another firestick and I'm still having problems casting from youtube on the phone to the tv unless I use a code. The issue seems to be with any phone that I'm using. Has anyone else faced this problem before?