I have a 2017 sportsman 570 that keeps overheating only 350 miles on it, rad is clean, and just installed new thermostat, and fan comes on at 199 and will run but once heating up to 210 or higher fan keeps running and temp will only drop to about 197-201. Any ideas why it won’t operate normally?? Also 1st time it overheated was in the winter on a 20 degree day while on a lake ice fishing. Thanks