Turn off power to the EFIS screen and wait for it to shut down and then power up and try it again.

Each EFIS screen with an AHRS should have its own OAT probe. The OAT probe is used for TAS and density altitude calculations on the EFIS.

You can set the Tach and Hobbs in Instrument Calibration > 1. Admin Settings > 23. Set Tach and Hobbs Time