I wouldn't be very concerned about the difference between the set temp and the lid temp. The controllers on modern pellet grills are generally calibrated to maintain the set temp at grate level, usually in the center of the pit. Since heat rises, the lid therm will always run significantly higher than that. Once you're able, check with your Maverick to see if the grate temps are close to the set temp. If they are, don't worry about the lid temp.
Just my opinion, but the readings you got when you tested your meat probe are certainly close enough for me, if it reads 211* in boiling water. I wouldn't quibble over a 1* margin of error. If it still bothers you, test again a few times under varying conditions (wind, ambient temperatures, etc.), then figure the average margin of temp variance. As long as you know what that variance is, you can adjust your cooks accordingly to get the accurate desired internal meat temp your after.