1st gen ring, mechanical doorbell, transformer. Does it need a resistor?

I've had a 1st gen Ring door bell for about 3 years and I charge it once a year or so . On several occasions, under Device Health it switches to battery, although it is hardwired. I have the Ring going into a mechanical doorbell and a transformer which I just replaced 6 months or so ago. On a call today with customer support, they said I need to use a resistor so I have one on the way. In looking further into this, do I still need to use one even if I have a mechanical doorbell? Is there any issue if I do use the resistor? I'm just trying to settle this so I don't have to mess with it any more.