Updates!
I followed-up with Sengled by email and they reached out by phone the next day to discuss (great customer service by the way!). Turns out the bulb is compatible with SmartThings for on/off and dimming, but the motion sensing component is not integrated yet. In fact, the customer service rep was surprised I was able to get the motion piece to work at all (said there were only a couple people who have had success with it, so maybe some of the early bulbs were different??). Anyway, Sengled has submitted all its documentation to integrate with ST, but ST has not processed/approved it all just yet. Until that integration happens, it will be hit and miss.
The rep did confirm the sensor is a PIR, so part of my issue may be due to having the bulb installed in a high portico where updrafting can occur. It also explains why I didn’t really experience issues in the winter, but did once the weather warmed up. However, sensitivity adjustment may be able to dial this out.
To Sengled’s credit, they offered to exchange my bulb with a new one (I declined) and give me a discount on a Sengled hub, but for now, I am going to wait it out in hopes ST integration is around the corner. In the meantime, I may try to leverage some motion enabled cameras I have via IFTTT to control the light.
Overall, I am still a huge fan of Sengled. With all this smart home stuff, you have to expect some hiccups along the way. Just means more tinkering to do, but hey, that’s half the fun of it, right? 