Serendipity isn’t updating and archiving old ones

I really enjoy using your app and find the Serendipities feature truly fantastic. However, I’ve noticed that my Serendipities are full (20/20), and I can’t receive any new ones. Sometimes it’s only one per day. I’m on a paid plan and I use Me.Bot every day 😃 Could you please let me know how I can delete or archive old Serendipities to make room for new ones? Or could there be another issue?

Thanks a lot 🙏