OK, I’m not entirely sure why, but it is now all working correctly.
I’m not entirely sure what I did to achieve it (And I truly hate that!) so I’ll list the things that I did do:
1. Upgraded to the 2.1.1 software and rebooted the OSPi.
2. Created a daily program that was scheduled to run every day.
3. Rebooted the OSPi again, via the web GUI this time.
4. Cleared the cache on my web browser.
5. Accessed the web page using a local URL instead of via a DDNS entry that points at the public interface of my router.
6. Deleted my test program, and went back to accessing everything as I always did.
I’m not sure which combination of those worked, or why, but all is good now.
Nice work all!