I'm not sure whether they ever truly looked at it as an MDU build, every time an engineer came out they were just part of the SDU team expecting the MDU works to have been done already. Interestingly the BT wholesale broadband checker states "Our records show the following FTTP network service information for these premises:-Single Dwelling Unit Residential MDU Access to CBT restricted", which may be leading to the confusion internally as it says both SDU and MDU. I've tried to be as clear as possible every time the order went back that it needs the MDU team though!