The FirebaseDB1 working well but FirebaseDB2 and FirebaseDB3 cannot working

[TAN_HOCK_WENG_STUDEN]

Hi, when I use more than 1 FirebaseDB module, only FirebaseDB1 works fine, while the other Firebase modules (such as FirebaseDB2 and FIrebaseDB3) do not work. MIT App inventor also reports this error:

Attempt to invoke virtual method 'com.firebase.client.Firebase com.firebase.client.Firebase.child(java.lang.String)' on a null object reference

These 3 FirebaseDB modules are located under the same Firebase URL link.

These are my blocks:

and this is my Firebase data:

The "RainSensorData," "SoilSensorData," and "WaterTankLevels" are the project buckets of the FirebaseDB2, FirebaseDB1, and FirebaseDB3 respectively.

This is the page of the AI companion:

The Soil Parameter, Tank Water Level, and Weather are under FirebaseDB2, FirebaseDB1, and FirebaseDB3 respectively.

The soil parameter is working well but data of the tank water level and weather can't work.

Any help with this would be greatly appreciated. Thank again!

[TIMAI2]

Just do it all in FirebaseDB1, and get rid of the other two, not needed.

[TAN_HOCK_WENG_STUDEN]

thank you very much!