Thanks for your quick response.
Yes, I first tried deleting both the other plugins leaving Podlove the only plugin and then I still had the issue.
Then I deactivated Podlove and reinstalled the other plugins, and the issue went away.
When I reactivated Podlove and refreshed the feed, it appeared the first time (a longer feed than before), but then when I refreshed the page it went blank and has stayed blank ever since.
I just re-tried to make sure - I purged the cashe, deactivated the caching plugin and then refreshed my feed. Still not working.