Calendar in the speak section shows 1 on 1s that have been deleted

For Saturday July 17 my calendar shows 2 1 on 1 conversations (09.15-09.45 PM GMT+2) that do not show up in the list. Harry Ness deleted the 1 on 1s and signed up for Sunday same time. This shows up in the calendar and the list. I cannot access the Saturday 1 on 1s, to delete them myself (it says “Page not found”).
My alternative account shows 2 1 on 1 conversations are taken. It looks exactly the same as a group conversation, which it is not. When you open the ‘Show times’ list, the 2 1 on 1 slots are there (in grey, not black), but cannot be ticked.
Clicking on “Gruppengespräch”
09:15PM - Reinhard: 1 on 1 conversation 15 30 Minuten
gives me a 404 error - “Not found”.

Thanks, Reinhard. We will look into it.