HI @Kevin_Lopez @Ryan_Durham welcome to Zwift forums to both of you.
We’re aware of the wrench icon disappearing after a few seconds, and we’re working on fix for that.
In the meantime, your Zwift Hub trainer will autocalibrate as long as the trainer is on firmware version 4.0 or newer, and you’re coasting for at least five seconds from a speed of at least 15 kph / 10 mph. See this Support article for details