Download approved 360 game to child's Xbox Series S

I have an issue where we have a child account setup on an Xbox Series S with various content restrictions set on it.

We are trying to install a couple of backwards compatible Xbox 360 games which are available for free from the store and are above the currently set age restriction.

We have been through the purchase flow multiple times for the games, which prompts me as the family organizer to approve the purchase, which I do.

Using the Xbox Family app, I can see that the game has been approved for this child's account, however when we go into the My Games menu the games don't appear.

I have been through the Xbox support site trying everything suggested like signing out and back in, restarting the console, refreshing the games menu, checking filters, checking for updates, etc. and nothing has made these games show up.

We have managed to install a couple of standard Xbox Series S/X games from the store which also required approval to make sure that the approval flow is working in some capacity for us.

It appears that it's just the 360 games that are causing problems for us.

The store lists the problematic games as playable on the Series S and X so I expect they should work.

Are there any additional steps required to play backwards compatible games which are above the age restrictions, but approved by a parent?

Is this an edge case which hasn't been caught and needs fixing?

Am I missing something really obvious?

Thanks for any help anyone can offer.

:)