Hi

For not getting old value:
1.Does the problem still occur if you only perform only one subscription?
Yes
2.Does the problem also occur if you replace "getOldFieldValue" with "getFieldValue" (which is equivalent in that context)?
Yes

Basically, I dont get any value using getOldFieldValue or getFieldValue.

For [object Object] problem
1.Does the problem still occur if you only perform only one subscription?
No
2.Does the problem also occur if you replace "getOldFieldValue" with "getFieldValue" (which is equivalent in that context)?
For getFieldValue I have [object Object]
and for getOldFieldValue I have null

Please let me know If you need any more details. I am glad to help out solving these issues.