Couple of things here. First, I wasn't able to reproduce the issue getting sync errors. When I checked out the sync errors for your portal (Hub ID 4772490) I saw a number of contact errors related to a more specific invalid property value error; I won't include the entire error here, but here's the relevant info from one of the contacts:
Big Game, Whitetail Deer, Turkey, Predator was not one of the allowed options:
Unfortunately I wasn't able to infer precisely which property was refusing those values; do you have an idea for which property those are being passed to?
Side note; if you still run into issues after investigating the invalid property value issue above, it'd be super helpful if you could include the full raw sync message request you're making that doesn't function as expected.