07 Ion 2 2.2L Temp Gauge Dead until A/C button pressed

I have a 2007 Ion 2, 2.2L, w/ 96,000 miles. Lately I noticed the temperature gauge stats at cold when starting the car and running it for up to 10 - 15 minutes. Then if the A/C button is pressed, it will snap to indicate normal operating temperature.

Anyone ever seen this? I replaced the ECT or coolant temperature. No effect. I was going to replace the thermostat next, people have said that may be affected. As far as I can tell though, the A/C blows cold air though.

Any comments would be appreciated. Thanks.