I’ve had the same problem and had 4 pairs of the new xtr trail pedals warrantied. Seems to be a problem shimano knows about, but doesn’t seem to be fixing?? Thinking of changing to the new xt trail pedals instead but they might have the same fault!
Had the same on 2 sets. Warrantied both. In the end replaced them with the new xt version that are a few grammes heavier but have been faultless. Baffles me why Shimano have not fixed this and keep just sending them out especially at xtr level. Also refused to admit this is a known fault.