Voltage issues pro 2

I have a ring doorbell pro 2 which has been hardwired using the new black DIR which came with the doorbell. The voltage keeps on dropping and is so inconsistent which is having an impact on the audio on the outside. I’ve had to hard reset the doorbell to get the audio working as i could not hear any sound coming from the outside. Iv had the doorbell for just over a month. Can you help with this please