If you start a movie or TV show, scrub a few minutes in, close the movie, go back to your home screen and open the widget is it still blank?
If you still don’t see anything after doing that could you get your log files and then upload them here please? https://support.plex.tv/hc/en-us/articles/201636593-iOS-Logs
@chfredrickson … thanks for your advice and I’ve tried the steps you suggested this morning and it updated the widget with shows. but 5 minutes later it’s back to ‘Unable to load’