Ring Doorbell Pro and Nutone LA600WH

My existing doorbell is a Nutone LA600WH which is on the compatible list of working doorbells. My friend gave me his Ring Doorbell Pro as he had to remove it from his old house before moving, and his new house already had a Ring Doorbell Pro installed aleady. It was working just fine at his house. When I connect it to the Nutone chime,I get nothing, The Ring light seems to start out glowing initially but it eventually goes out and I get nothing from it. I checked my doorbell transformer (which was only 16V), but I recently upgraded it to a 24V transformer but the results are the same. I've had the Ring Doorbell plugged into a USB port in my computer (in hopes it charges the capacitor). I am going to replacing the old wiring and try it in a few days. If this doesn't work after that I will update it further, but I had some questions on how to install it. Reading the Nutone installation manual, it says that a diode needs to be placed on the terminals at the button itself with the silver stripe on the transformer. This works fine without the Ring Doorbell, but I don't know if it needs to be installed on it when using the Ring. Someone posted in the forum on using this same setup, but thechime wasn't playing the whole ringtone. I suggested the diode and he said it didn't need it on the Ring setup. I also tried contacting Nutone about it, and they said to contact Ring to ask them since they are the ones who listed it as compatible. I have tried to contact Ring, but I haven't been able to yet. Has anyone had any success in installing the Ring Doorbell Pro with this particular model and had it work without any issues?