Cat scraper Trans oil transfer

Wondering if anyone out there has come across this problem.
I have a 627E Cat scraper that is transferring the transmission oil from the trans into the diff housing.
I have drained the diff so no oil was left in the housing, then filled the transmission and started the machine and the transmission oil started flowing from the diff drain bung.
Has anyone else had this problem and do you know where the transfer would be occurring?

Cat scraper Trans oil transfer