Getting kicked out of videos after 1min

Hi, I've been using it on a Firestick and it's been great for about a 1mth, but in the last couple of days when I start watching a video within a minute or two it closes the app and l'm back at the home screen, I've cleared the cache & the app is up to date. As a test I've watched the same video on yt and there doesn't seem to be any ads, breaks, so I'm not sure why this is happening now?Thanks