YouTube issues

Two weeks ago, after doing an ios update on my iphone 8+ & the youtube app, I am no longer able to cast the FB videos to my tv as I had been doing before. I have uninstalled youtube & reinstalled etc with no changes. When I try to play the video from the FB site to open in youtube it goes to youtube & then wants to know what browser I wish to open youtube in then seems to go to the app but never shows the option of playing the FB video I am trying to start & cast to my tv. I remember seeing a small youtube icon that was white on the video on the FB site that I would tap to open the video in the youtube app, it is no longer there, only when I tap the watch later icon does it go to youtube but the video is not there to play or add to the queue. I have already sent feedback to youtube & an email to FB but thought I would see if anyone else has encountered this issue & has figured out how to fix it?