I have a 2017 29H as well, and it’s driving me mad why the awning sometimes doesn’t retract. I’ve never had to manually retract though, as it will eventually work. It’s the LCI Solera, 12v model. The retract takes more power than extend, so I think it’s a low battery issue- although you would think being plugged in or running gennie would solve that problem. I’ve never found the smoking gun as to why it won’t retract- but I have found that pulling the pivot points down seems to help. I think in that position there’s less force required to retract (although the manual specifically says you don’t need to do this; manuals sometimes lie like rugs.) And if the battery is slightly low, that little bit seems to help.
I’ve been meaning to follow the power lines to see if Thor did something stupid, like connect it to the chassis battery instead of the coach. That’s the only thing I can think of that would give these symptoms. If that’s the case, turning on the engine would help.
Here’s our manual retract page, btw