Cabinet quest won't complete?

I've completed the cabinet quest from Season of Assembly at least 4 times in the past 2 days (I tried it ages ago but got frustrated then too and moved on to complete other seasons), I'll get the prompt saying I'm done and asking if I want to return the cabinet and I click yes, I'll get teleported back to the starting point (where the prayer circle was but then isn't anymore) then nothing happens. I'll go back to the treehouse via the tunnel and the guide will have a red dot and behave as if I've still got to go and complete the cabinet!

Any ideas what I might be missing/doing wrong? 😭

PS really glad to have found this community on lemmy, not sure why I didn't think to look sooner!