OK, worrying thread here. Installed a Ring Pro today that was purchased as a black friday deal.
It worked fine for about 15 minutes and died while I was installing the Alexa skills.
Still measuring 18V at the leads of the doorbell (used the 12V on the transfo that came with it, the 24V output on the transformer reads 30V so I choose not to connect to that one but use the 12V instead wich results in 18V at the door).
Contacted customer support and they are sending out a replacement, but after reading all this…