I have my Fios remote (p265v5) programmed to turn on my LG tv and control my Samsung soundbar. I used the key programming technique to get the vol+/vol-/mute working and everthing works perfectly for several hours. The problem is the next morning the vol+/vol-/mute keys no longer work. The remote seems to forget its custom programming. It has done this several times and I don't know why it won't remember the custom key programming. I have tried programmign the other remotes in the house but they don't work well. When they program holding the vol key only moves the volume by 1 and won't keep moving. The remotes all appear to be identical.
So on a hunch based on another thread that mentioned older remotes had better compatability with some products I bought a P265 V3 remote off Ebay for $5. I programmed it using the key technique to make the power turn on/off the TV and the volume/mute work with the soundbar and have had no problems for a week. None of the V5 remotes will work or stay programed but the V3 works perfectly.