Thanks for checking Captain Callum. That was very nice of you to do so.
I checked my zoo save more carefully last night and this morning. I have 11 talk points in it (I love them!) and found that 6 were functioning correctly and 5 weren't. Only the Clouded Leopard habitat displays habitat not containing animal but perhaps it has something to do with the habitat design since talks are taking place. I did, however, find an issue by checking all talk points and have filed a bug report for it:
https://issues.frontierstore.net/issue-detail/51837
I replicated the problem in 2 different zoo saves. If seating is linked to the talk point and standing guests aren't allowed, then no guest count for attending will appear in the animal talks menu tab. Changing the talk point to allow standing guests does allow the guest count to display. This isn't actually game breaking for me since the guests seem to gain education but I wasn't sure how much the guest count contributes to the educational rating of the zoo. Hence, I opted to file the bug report. If anyone reading wants to check their games and contribute to the report, if seeing the same issue, please do so.
I'm glad the Dhole situation cleared for you abhiwan_kenobi. I see seating in your pic for the Siberian Tiger habitat, so you may want to check and see if talks are taking place and whether or not any guest count registers for you.