Chiming in… Dealt with this but on a ring branded doorbell, I suspect it’s the same here.
The doorbell is designed to use with an AC volted chime, but if there’s no chime you’ll need a resistor to imitate the load a chime transformer would normally have built-in. The doorbell is like an LED light and can’t run unregulated or it can become unstable / burns out the transformer or doorbell eventually / weird things also just happen in this form. Running a low amp AC wall transformer may work temporarily, but the doorbell will be asking for all the power it can get, significantly shorting the life of the transformer. The resistor though would help regulate the load. It’s possible there are wall transformers with the built in resistor too as a specialized item.
Keep in mind that when you push the doorbell button, you are directly shorting the contacts (to complete the circuit of the chime itself causing it to actuate, which is something you don’t want to do (short circuit) to a transformer without a resistor/load.
I suspect support doesn’t quite understand how the engineers designed it, but I also suspect they could release doorbells with just a DC in port option too for houses without a system already in place to simply keep them charged…
For a resistor, you’ll want something similar to this: https://www.amazon.com/Ring-53-023183-Wirewound-Resistor/dp/B07WF98SVW
Hope this makes a little sense. Let me know if I missed something.