Podcasts on Apple Watch SE not syncing with my iPhone

My Apple Watch SE was syncing podcasts from my iPhone completely fine up until the other day when it stopped. I have not done anything knowingly to change anything.

I’ve tried everything and when I thought I’d fixed it - went out for a run, finished the two podcasts that were in the ‘Downloaded’ folder on the watch, then stuck it on charge so it would download the next lot for the next run and surprise surprise…..it stopped downloading them again. It says you can add podcasts manually blah de blah but there is nowhere to allow me to do this!

I am so fed up as I really wanted to listen to podcasts when I run instead of music.

please someone help :S