Values were not written in DB in Write to multiple data store entity

We can't say anything without having a look at the configurations you have done in WMDSE. Can you provide more details and add supporting screenshots to help us figure out the issue here?

It look something like this 

You are passing the entityData in wrong way. It should be like:

{
  a!entityData(entity: cons!ENTITY1, data: pv!data1),
  a!entityData(entity: cons!ENTITY2, data: pv!data2)
}

Also, please have a look at the documentation of WMDSE smart service.

You are passing the entityData in wrong way. It should be like:

{
  a!entityData(entity: cons!ENTITY1, data: pv!data1),
  a!entityData(entity: cons!ENTITY2, data: pv!data2)
}

Also, please have a look at the documentation of WMDSE smart service.