Looking at battery levels over time, I noticed between 20 and 21 February 2019, some (not all) tag battery voltage levels dropped in concert. Since then battery levels had been steadily dropping. Some more than others. For example the water sensor tag battery had been rock solid for over a 1 year with capacity at 90% before this time. Now its battery has steadily dropped to 15% (as seen in the app) at this point!
About 2 weeks ago my internet connection was out for a day. After that was fixed most of the tags did not reconnect.
I migrated to the new 2.5 sec response time in an attempt to reconnect them. They eventually all came back at different times but some drop out of range now and then.
After a week of observations, I noticed some of the older tags are ignoring the configured update intervals - these tags are not the new type with the multi data point logging special option. These older tags that were configured to update every 10mins and was working as expected until these incidents.
PIR sensors not detecting reliably, sometimes not at all or updating after more than 5mins in contrast to before where it would notify consistently.
Android App push notifications no longer working at all. Confirmed Andriod notification permissions enabled for the app.
I've started using the tags for about 2yrs and batteries used to last for about year with reliable operations. (included graph of all tags and battery levels over all time - you can see the steeper rate of decline over of the last few weeks compared to baseline). Now tags would go out of range seemingly randomly.
An updated change log would help in isolating the cause, whether it's my environment or a change to the service.