Welcome to the forum.
Out of curiosity, are you on a UFO or FCCC? Weren't Lattitudes and Destinations built on both? No matter, the slides and jacks are a Winnebago installation and not something the chassis maker installed. I believe both had HWH for the hydraulics to operate the leveling system and slides ...others can correct this if I'm wrong.
There are a lot of HWH experts here so hopefully somebody --including azpete
(Paul) who works for HWH-- can help diagnose your problem.
Otherwise, I would think Winnebago would be the first place to call, if nobody here can help, ahead of HWH as there may be a procedure you're missing, etc.