"Is that correct?"
3000 - is error code meaning, that sensor data is unavailable. I.e device/FW tried to read data from sensor but was not able to find it. After 5 attempts (@ old FW) -> 3000 error code is set. @ new FW -> 30 attempts failed to read -> 3000 error code is set.
But as you noticed, only for temp/humidity IO. Battery value - stays on last read.
https://wiki.teltonika.lt/view/FMB_AVL_ID - more on error codes. See "BLE 1 Temperature".
The problematic behaviour is caused by the fact that FMB devices sometimes fail to detect TZBT sensors. And also early FW implementation was too strict. In regards for data reading from TZBT sensors.
To solve your problems:
1. Update your device FW to 03.18.16 FW. You can download it from:
All devices even FM3 can use this 03.18.16.
2. in FMB configurator -> Bluetooth 4.0 -> common settings -> BT power level -> configure as 7.
3. TZBT data reading was improved in 03.18.02 version. But i'd suggest for you to use 03.18.16 as its latest "stable" version.
In this 03.18.16 - you should not get those 3000 errors as often as you do with older FW versions. If at all.
4. Also a point to consider - is to configure TZBT sensors with higher "BLE transmit power level" value aswell. You can do this by using "Humiture recorder" App @ google play store:
This app is native TZBT sensor manufacturer application.
Default sensors password is "00000" or "000000" ie 5 or 6 zeroes.