Pro 2 install with new wiring

Hello all.I just purchased the ring pro 2 doorbell and doing a complete new install as there was never an existing doorbell or chime. At this time I will not be using a chime but when I do I will get the ring chime. I went and got the correct transformer needed for the ring pro and ran new 18g wire for doorbell. When I turned the breaker on I was not getting voltage off the transformer. So figured maybe I got a bad one so went and got another and wired it up without the doorbell wired to it and verified I had voltage from the transformer. All was good and had about 19v from transformer. I wired the doorbell to the transformer and went to check the ring pro and still had no power. I went to test the transformer again and once again had no power off the transformer again. So now I have blown 2 transformers and not understanding why this would be happening. I’ve read multiple posts and many people have wired directly from transformer to to ring pro 2 with no power pack or resistors needed and other saying you must install a 50w wire wound resistor for this to work but even that seems in clear. Any assistance on wiring a brand new transformer directly to a ring pro 2 is greatly appreciated.