It's now 2023, I recently bought a Reolink Duo 2 Wifi and this exact same issue from years back still exist for this new camera model. Whenever the camera switches on the IR for night vision in the evening when it starts getting dark, the motion sensor is triggered. I have the motion sensor set to the lowest value possible (1) and have downloaded the newest firmware for the camera. The suggestion to solve the issues has for other models been to set an alarm delay, but for the Duo 2 model that can only be done for person/vehicle/pet alarms and not for the motion alarm, so it is not a viable option here. Even if that setting would exist for motion alarms, it would not be something that I would like to use as that might make the camera not record someone tampering with it.

I think the obvious solution is to turn off the motion sensor right before the camera switches over to IR and turn it back on again right after, and that should be implemented for all Reolink camera models.