Mechanical chime does not chime

Ring doorbell pro has been installed by a electrician and cannot get it working correctly. Tried many things and double checked the product. -Voltage at 20v -wires all secure on the doorbell and mechanical chime -wifi is strong to the unit -no Alexa or google home taking notifications -doorbell shows proper video and motion notifications -when doorbell is pressed, it makes a chime from the unit itself from the outside but no chime from the mechanical chime in the home -Reset button has been held for 20 seconds and doorbell has been reset -Power has been shut down for 10mins and powered back up and reinstalled using the given install video -On the app, the mechanical chime has been selected and the in home doorbell is on. -have deleted the app and unit from my ring account and all reinstalled -reinstalled the old doorbell and works perfectly fine. Please help.