Well no one seems to be helping you here so how about if I start the ball rolling and ask some questions that come to mind regarding your couch issue:
1. Is the foot rest on one or both sides not coming up? If only one side has a problem how does the working side operate?
2. I “assume” this is an original couch (not a new one), so how did the foot rest(s) come up before this problem? Maybe the "coach or couch" is new to you?
3. La-z-boy style couches I am familiar with, typically use a lever (not enough room in many RV’s for side levers usually); or they use a button on or in the arm rest to release the foot rest/recline mechanism.
My experience with La-z-boy chairs and couches (non-RV) in the past, was that the wood screws holding the mechanical systems in place on the frame would back out over time from general use and then the metal lift or recline mechanisms would jam. After many couch turn overs to re-tighten constantly loosening fasteners, it long ago became resident at the local recycle dump.