Quick PSA.
After changing the batteries of my Philips Hue Motion Sensor it started to have connectivity issues. Every couple of days, the motion sensor became unavailable in Home Assistant and I had to re-pair the sensor in ZHA for it to start working again. The sensor had been working flawlessly for over a year prior to the battery change.
What fixed the connectivity problems: good quality AAA batteries. Although the first battery replacement was done with (private label) AAA batteries from a reputable DIY store here in NL, they turned out to be of poor quality and were the root cause of the connectivity issues. After replacing them again, this time with expensive batteries from a reputable battery brand, I haven’t had a single connectivity problem in weeks.
Took me a while to figure out… so I hope this information renders useful for somebody somewhere in the future 