Any updates on your issue?
I'm having the same issue right now. This is the second time around for this. Unfortunately this time is not under warranty. Keystone customer service referred me to Lippert. I just sat on hold for 20 minutes with Lippert only to get disconnected.
Landing gear will only work with remote, not manual. 30 amp fuse is good. I reset the remote function at the request of Keystone but that did not help. They told me to call Lippert. All other functions work properly both manually and via remote.
I will continue to try to contact Lippert...