After subscription renewal a family member cannot access PRO

I have iOS family sharing set up. My three kids and wife all access Infuse from their iPads. Yesterday my Infuse subscription renewed. Two kids got prompts to upgrade to Pro. When I confirmed the renewal, one of their devices (iOS 12) continued with Pro (as before). The second devices (iOS 10.3.3 - the highest supported version for this device) is still offering an upgrade and refusing Pro features.
I’ve tried signing out of iTunes and back in, signing out of Trakt and back in, updating Infuse, and restarting the iPad. None of thes worked.

Did it give you the option to “Restore” along with the offers to subscribe?

Yes. And the restore did nothing.

Is trakt signed into on all devices? I remember reading another post somewhere that licensing can be shared through trakt.

You may want to recheck to verify that it’s set up for family sharing. It sounds like the one on 10.3.3 doesn’t know it’s on the family sharing plan. Are you sharing other apps?

Checked that already. When looking at the App Store on that iPad I can access all purchased apps of the family.