Hey @ss109! Thank you for sharing your experience and steps taken in great detail. As this happens at night, the Doorbell Pro does pull more power at night for the night vision operation. This is regulated by the Pro Power Kit, as you know. Good call checking the Pro Power Kit, it’s possible this is the culprit.
The spare parts kit on our accessories page at Ring.com will provide a Pro Power Kit, among other parts. I recommend starting with this, as your transformer is likely providing sufficient power. Please also double check wiring for variables such as length of wire run, eroding/ fraying wire causing a short, or even wiring being too thin, causing resistance in voltage. I hope this helps! 