[jim256]

after driving 2019 CR-V for 20 minutes, and engine is at operating temperature, temperature gauge went to zero, then gauge started moving up and down. anybody having similar problem? What's the cause and how to correct?

Dealer, Brown's Honda City, Glen Burnie MD is clueless to solve

I can tell you that I don't see any behavior like that, the gauge is relatively stable when warmed up, on days when the temps are in the 20's or 30's in the morning. '19 CR-V 1.5 liter. It seems they ought to at least change the sending unit and see if it resolves. The red needle never disappears after warmup, if that's what you mean by zero.