Disappearing sprint work-outs?

Hi, today I woke up to find an error with a number of planned work-outs for two of the athletes that I coach. For two different planned work-outs the title and time still exist but the body of the work-out has disappeared. Opening the work-out doesn’t work and copying the work-out triggers the following error message:
‘Got 500 Internal Server Error parsing workout description for athlete i******’
Both of the work-outs include repeated sprints, so I can imagine that is significant. For at least one of the two work-outs it is also impossible to open the same work-out that already happened last week (the planned session, not the actual session file in this case).
For now it is fairly easy to work around the error by just writing the sessions again but that’s a bit annoying, and if it happens again it’ll start becoming a problem. I hope there’s an easy explanation, thanks in advance!

Not a solution to the actual problem but if the correct workout is somewhere on the calendar, you can Alt drag (on Windows - don’t know the iOS equvalent) it to copy it on another day iso rewriting.

Should have said this was the case for multiple copied work-outs in the calendar. That said, the work-outs have somehow reappeared, so whether someone has done something or it has magically fixed itself, the bug seems to have disappeared as quickly as it came.