Classes in both DAs and EAs can cause issues if using EA groups
When pushing a class using EA sync and EA groups that also have objects that are a part of standard DAs you may encounter services created using a non-expanded key.
This is because DAs do not have EA groups attached to them so the key is unable to resolve and results in it being sent as a standard string.
Use group filters on your discovery to segregate instances that are a part of DAs or EAs and create a payload appropriate to the instance specified (eg. either ignore the items in DAs entirely by creating a discovery using only a standard payload for them or by creating an EA sync discovery that does not reference EA groups).