Central Locking of Hab Door Stopped Working

Our Broadway fb was delivered new (a 2020 build suspended at dealer by lockdowns) 
in April 21. 
Remote fob has different buttons to open cab doors 
and the habitation door. All has worked perfectly for 
3 months. But now the hab door won’t open or lock remotely. 
Requires use of the manual key. Cab doors unaffected. And though the hab 
door won’t lock or open on the fob button press the step still extends and retracts 
 to the button presses as before. 
Dealer a long way away and it’s an irritating not a 
disabling  issue worth a special warranty visit in season. 
Anyone any advice on what to check or do?  
Is there a separate fuse for the Habitation door 
remote operation? Are there accessible contacts in the
hab door lock to check or clean?
Any help gratefully received.

WD40 on all lock contacts is a regular routine for me to ensure habitation central locking keeps working.

Thanks. Will definitely try that.  WD40 was of course an indispensable aid applied to the distributor cap of the first 1960s Minis to keep them going in the rain so why not a 21st century hab door?

That sounds plausible. Can you help further?  Looking for location of the contact pins: in the door I presume ( not on the frame?). 
Everything is buried in the door trim plastic. Have squirted wd40 wherever there’s a gap to no effect yet. On my last Motorhome the contacts were visible and could be adjusted. Where exactly are the two sprung pins on your Nuevo to compare with my Broadway? 
Thanks for your help.

Brilliant. Found them. 
Thank you so much.

Solved. Cleaned contacts once identified,  then leant on bottom of door while operating the remote. Bingo. Tried again without pressure on door and it still worked. Door mayb need adjusted soon to pull it in slightly. Not obvious how to do that but now know what the issue is. Thanks to all for invaluable help. 
Off on holiday tomorrow in the van. Good to have things all working!