New fields in the existing SAP Analytics Cloud model

Hello,

We have an existing model in SAC over BW query with 50 fields.

Now we want to add a new field.

After the query is loaded into a draft. All 50 fields that were mapped go wrong

And now need to re-map all 50 fields again? Why?

Is there a way to copy the old mapping and make only mapping to new field?

Thanks,

Eden