So I had my incline switch become inoperable last week. Now that I had time I decided to dig into the issue. In my case, much like the OP, the seat back would not incline but would recline. The switch physically felt odd. It sort of snapped in the recline position and would continue without me holding the switch. Then in the incline position I would hear nothing and it wouldn't feel like anything was happening.
So here's what I dug into. I pulled the seat out, pulled off the switch fascia, then pulled off the switch panel. It took some pressing onto the plastic tabs but I was able to get inside the switch housing (breaking some small portions on the way but nothing vital) until I was able to see exactly what was going on. Turns out the switch contact and plastic that moves it was both burnt and melted. I gave the contact a clean and rebuilt the prong on the switch with some plastic that broke upon removing the panel using a solder iron. After reinstalling things weren't quite right due to the new plastic being a bit too big. I pulled it again and shaved down until it was almost identical to the existing prong. Reinstalled everything and now it works just fine.
I hope this helps others as I haven't seen much of a fix for this in threads going back to 2011/2013:
DS Seat will recline, but not move back
Power seats won't incline
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