Yup - no surprise. Short version: if you’re seeing the same problem as is described in this thread, buy a good battery and your problems should go away.
Their batteries are not good AND there’s something about the sensor software and/or hardware related to the battery level detection that is flawed, in my opinion. There’s a relatively big current draw when the device first starts up (after you insert the battery), and that causes a brief drop in the battery voltage of some batteries. The device software sees that lower voltage during bootup and never tests the voltage again - it just stays stuck in the infinite loop of flashing every 10 seconds to report a dead battery. But during normal operation after bootup is complete, the current draw is much lower than on bootup, even when it wakes up and is flashing the LEDs. So the voltage never drops very low again after bootup is complete and the battery should work just fine.
If only Wyze would update their contact sensor firmware to allow for a second voltage check after bootup is complete, it seems possible that many of the battery problems reported on the Wyze threads could be prevented. I’m not sure if the contact sensors even have the ability to handle firmware updates, though. I have seen camera firmware updates and app software updates and even one sense bridge firmware update. But the sense bridge firmware update did not update the contact sensor firmware as far as I can tell (the only “version” associated with contact sensors is the “plugin version”, which did not change after the bridge firmware update from what I recall).
I have two different sets of contact sensors which definitely behave differently with the same exact battery. All sensors across both sets are connected to the same, single sense bridge, and all report the same “plugin version” (not sure what that even means). The first set of sensors will follow the LED flash pattern described in this thread and refuse to connect to the bridge - but work well when the “dead” batteries are replaced with new batteries. The second set of contact sensors, when using “dead” batteries from first set of sensors, display a different LED flash pattern when they boot up. And then they communicate just fine with the bridge and don’t even report a low battery (battery levels report as “normal” in the app). And this second set of sensors have all been working beautifully for several months now with the same “dead” batteries from the first set of sensors. Put the “dead” batteries back in the first set of sensors, and they will display the same flash pattern as described in this thread and will not communicate with the bridge at all. Give that first set of sensors a new battery, and they work just fine again. Put the “dead” batteries back in the second set, and the sensors in the second set work just fine as before.