Hi there.
A couple of things.
Even if the hub was not capable of providing CP, it should be recognized by the APIM. We had mane cases where users upgraded their old Sync3 version to 3.4 and the hub was working fine, a popup may appear that said “hubs not supported”, but the hub had power and was usable for playing back music, or charging a phone. Even Android Auto could work, but not CP. For CP as you have read, you need to change the hub → Media Hub, CarPlay Compatible - 2015-2020 Ford/Lincoln - SYNC 3
So that tells mes that the hub is not the issue, there’s no parameter for the APIM to enable or disable the HUB, it’s just hardware right?.
I can’t really say what’s wrong with that, but getting 2 faulty HUBs is quite odd as well.
Do you have an android phone to test?.