I experienced that once,(HWH 610 system) called a mobile HDT repair shop, When the man arrived he asked me to activate the leveling system and allow it to complete the cycle.
After completion,I pushed store, after that completion the air springs filled and everything was normal. That lesson cost me $190.
I hope that is your solution too.
2000 Winnebago Ultimate Freedom USQ40JD
, ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG 11B5MX,Infantry retired;Good Sam Life member,FMCA." My fellow Americans, ask not what your country can do for you, ask what you can do for your country. John F. Kennedy