Wayne.... I think that's what the cause was. My smoker is located on my backporch which gets sun in the afternoon.... It worked fine from about 8am until about 2pm when it started to get direct sun on it, then it flipped out.
I tested it again last night and it seems to be working fine now. Although when I started it back up and set the temp to 175 just as a test temp.... it went all the way up close to 300 before it clicked off and dropped down to 175 where it maintained temp just fine. I know it's supposed to temp spike some at the beginnning but I didn't think that much.
Anyway... yeah, I think direct sun on the controller was the problem so I'm going to keep it shaded next time.