Ecommerce bridge api endpoint "Check the sync status of an object" returns 400 errors

[EDevTeam]

I see a large number of 400 errors in the responses to the "Check the sync status of an object" endpoint, but most of the contacts and deals (which are checked) exist.
If I then send a separate request to double-check, the 200 response comes with the correct data.
How to prevent 400 errors?

Thanks!

[dennisedson]

@zaklein , @himanshurauthan ,  what is your method of dealing with this?