I got my Forrunner 255 music a couple months ago. Since the beginning I've noticed every button has its own feedback. Mushy or clicky, a distinct sound of a spring etc. but now the middle left button also sticks. That is, the button has no tactile feedback, but it does work. Now I've noticed the left lower button does the same sometimes. This is an intermittent problem. Sometimes there might be a a few days where the buttons don't stick and then they suddenly stick again.
I've contacted Garmin but they say that this is totally normal. But I do believe this is a quality issue, something is wrong with my watch. I had been hoping for better customer service on a basically new watch.