I bought a refurbished upright piano (Yamaha U1D). The keys feel a bit stiff, and sometimes if I hit a key softly it doesn't make any sound at all. It didn't have this problem when I tested it in the showroom, where it played well. The problem persists after tuning (I wish I asked the tuner more about it). I did ask the tuner about one particularly bad key, and he removed it and "cleaned" the felt area around the balance rail pin by sticking a rod in there and pushing it around. I have a dehumidifier rod inside it and a dehumidifier nearby (average humidity around it is 45-55).
Perhaps I just need to clean out those balance rail pins, but it's weird that it would suddenly become like this. I just tried it in the showroom days before and it was fine. Is humidity the only difference between the places? Or could the move have shifted something?
EDIT: Additional details: The showroom was pretty large, although with low ceilings. I think tile or wood floor? My room is large with a high ceiling and tile floors. I think it was moved by professionals, but I didn't get too many details on them. But they seemed like they moved many pianos before. It was only moved around 2-3 miles.