Did restarting change behavior at all?
There is a known, uncommon defect on some of the PIR sensors where the solder points (generally backside) short on one another due to the sensor’s dimensions and the amount used to hold them in the PTH holes/board effectively - usually a quick inspection and touch up with a soldering iron can fix it; this user Issue regarding Sparkfun MLX90640 110 Degree Sensor / I2c doesn't detect sensor had a more serious case where they implemented a spacer under the sensor on the front side and re-soldered the rear successfully
If you can take a look at your unit’s soldering and feel free to modify it if you see something wonky; if that’s not an option for ya let me know