2006 Durango, hemi, 178,000 on truck, 78,000 on new Jasper engine.

It’s -10 degrees here and I had a small leak at the t-stat housing. instead of tearing it apart to fix I added a half bottle of Bars Leak. The leak stopped but the next morning I get a few blocks from house and the temp gauge was just up off the bottom when the needle dropped to 0 instantly and at Same time the temp light came on.

I pulled over, shut it off and found no leaks. Started it up and all was fine. Needle and gauge read correctly.

This morning same thing happened. I shut it off while driving and restarted and all read fine again.

Did my stop leak gum up the sensor?
I may replace sensor and t-stat

any ideas?