digital door chime stops mid cycle


My comaptible digital doorbell which i have had hooked up to a ring pro has stopped going through its 8 tone cycle. I unhooked the rin pro and connected the doorbell manually and it cycles through all of the tones. Ring customer support goes down through the list of troubleshooting to include changing the seconds on how long the signal sent to the relay should ring the doorbell with no luck. I purchase a new ring pro on their suggestion and it is doing the same thing. 6 second setting will almost complete the 8 tones , but changing it to the 7 second, 8 second setting only allows the bell to ring 2 1/2 tones. Has anyone had any similar experiences? Customer service went down through the same check list they are required to and the solution is to send me another doorbell. Any help is appreciated. Thank you.