Problem with Ring Doorbell

Hello, my parents bought the Ring Doorbell Plus. I tried to install it for them, but I am having problems. My parents upgraded their transformer from 10V to 24V. They have wifi and two chime boxes. I installed the doorbell and set it up via the app. Got the doorbell working along with the camera. The problem is that the chimes do not work. And then as I was trying to troubleshoot the chimes, the doorbell stopped receiving power and it does not work. There are two doorbell chimes associated with 1 doorbell. So when you ring the doorbell, the first chime goes off in a single ding dong and then the second chimes goes off as a multi tone chime that lasts a few seconds. I believe the first chime (located by the front door) is mechanical. I am not sure about the second chime (located in the basement), but it was installed probably 25+ years ago and my guess is that it's also mechanical. First I installed the pro power kit on the first chime. The Ring doorbell worked at the doorbell, but it was not getting the two chimes to work. I then moved the pro power kit to the second chime. At first the doorbell kept ring on its own over and over and over again. I adjusted the wires in the chime and that stopped it from ringing over and over on its own, but an irritating buzzing sound was coming from the chime. I tried to adjust it again. That's when I noticed the Ring doorbell was offline. I tried deleting the Ring Doorbell on the app and redoing the set up thinking maybe if I redid the setup with the pro power kit on the second (basement) chime, it would work properly. However, that did not work b/c the app is telling there is no power going to the Ring. I never touched the doorbell when I was trying to figure out the chimes. Yes, the circuit break is on. 1) Why is my parents' Ring Doorbell not having power go to it? Where's the issue? 2) Where does the pro power kit go? First or second chime? According to a search, when 1 doorbell makes two chimes ring, you only need one pro power kit. So I know I don't need a second one. Which chime should it go on? Thank you!