Ring Doorbell going off line.

Morning girls and boys. I recently fitted a Ring doorbell and spotlight cam, the Ring doorbell is on a 24Vac supply via a resistor (though to be quite honest I'm not sure I see the need for this, but hey ho) Spotlight cam with battery and solar panel. Works great apart from this morning when the doorbell had dropped off line and required a reboot by removing the battery for a few seconds. Now, I live in Brazil where the mains supply is not always the cleanest or most reliable. The transformer sits quite a long way from the doorbell, probably about 30 mtrs so quite possibly picking up some RFI along the way, which may be upsetting the beast. A few months back I fitted a couple of doorbells for a family member in the UK also fed from a 24vac transformer, and where the mains supply is somewhat better, however one of them does the same thing from time to time, requiring battery removal. This one probably has about a 10 mtr supply cable. Anybody having similar problems ? And is an RFI filter mounted locally to the doorbell likely to be of any help ? Or possibly powering with a solar panel ??? Thanks in advance for any suggestions.