Hi there, @MarkH1! This concern is often related to power variables. Checking power first will ensure that your Doorbell Pro has enough power to not only light up, but to operate and connect as intended.
Check out this hardwiring checklist which helps greatly in considering all power related variables during setup or troubleshooting. Once you’ve confirmed that power is sufficient for operation, please take the Doorbell Pro off the wires for several moments, then reattach the wiring. Allow up to an hour for your Doorbell Pro to charge up with power, then attempt a setup.
As mentioned in the other threads you’ve posted in; if the above steps do not help to resolve your concerns, our support team will be happy to take a more in-depth look for you. Please give our support team a call at one of the numbers available here. We’re taking additional steps to protect our team and help reduce the spread of COVID-19, so this has resulted in longer than normal wait times. If you are outside of the US, please read our response to COVID-19 here to see how to contact support.