EDIT:
After reviewing the sheet for the calculation I found the error:

One of the cells there was synced with quantity. I have no clue how that can happen.
That sheet was never edited in that way to have synced fields

So I got stuck with the Quote Calculator because of this error:

"Multiple cells are updating the same field of the same record!
Unable to determine which one to choose"

I cannot figure out whats the problem. I checked a dozen times back and forth:
There are not multiple cells synced to the same field of the same records.
I just want to push quantity and unit price to the quotation, from just one single row of a product.
If I delete the field sync for quantity, it pushes the unit price to quantity as well.

Did I get something wrong? Bad thing is, the quote calculator is poorly documented as of now.

Any help is appreciated.