For us it had to do with the fact that we use specializations AND generalizations
We have the following situation and got a fix:
Aansluiting (generalization)
AansluitingGas (specialization)
AansluitingElektra (specialization)
AansluitingWater (specialization)
AansluitingCAI (specialization)
Now a colleague of mine got the very good cheating idea to switch off the sync for the generalization (set download to “nothing” in the "sync configuration” in the “Native mobile” navigation profile)
For now it works