I had no issues with any of my Inkbird sensors from approximately 2020 until my most recent purchases, starting in April of this year.
What seems unusual is that the extreme battery drain issue appears to affect only the newer IBS-TH2 Plus sensors with the temperature-only external probe purchased between April and now. These units are all running the latest firmware, version 2.7.0, yet they are draining fresh AAA batteries in only a few weeks.
By comparison, the IBS-TH2 Plus sensors with the external temperature-humidity probe, purchased around the same time and used in similar conditions, do not show the same extreme battery drain.
This strongly suggests that the issue is not related to my usage, settings, battery type, or environment. It appears to be specific to the recent batch or version of the IBS-TH2 Plus temperature-only external probe sensors. If there were serial numbers on these sensors, I would bet they were all produced at about the same time.