I tried looking for info on the 29MV but didn’t have any luck. The design must be different for this model because on mine I have the macerator hose which is contained in a small compartment and then I have a valve access compartment which is open on the bottom so no restrictions on hose size at all.
Hopefully someone with your model will chime in and answer your question. If not, then I would place a call to Jayco Motorized CS and ask for clarification. It is possible that the wrong size port was installed. Unless your dealer has a technician that really knows his stuff I wouldn’t put much faith in them being able to help you out. Go straight to Jayco and if the CS rep can’t help you ask for a tech who can. Good luck.
2016 Precept 35S