Sounds like you might have a slight leakage in the holding valves/solenoids near the hydraulic pump. See if you can down load the owners manual for the hydraulic pump and follow the trouble shooting guide. The other possibility is when you had all the jacks down and slide out you sucked in some air and the air will compress some allowing the drift. Follow purging air in the owners manual.
Also look for any signs of oil leaking from the hoses and rams.
2014 Coachmen Pursuit 31BDP
2016 Ford C-Max Energi
1987 Chrysler LeBaron Convertible
FMCA Member #F438633 - Good Sam Life Member
Coachmens Owners Group Member