Hi Matthias, maybe you used the SimaPro version, SimaPro does not understand data quality values (or, puts them in the description field where they cannot be used in calculations), therefore they are not accessible as data quality in openLCA.
However, when preparing a database from SimaPro to openLCA, we often manage to "dig out" these from the description and put them into the data quality fields in openLCA, but we do this via queries.
Best wishes,
Andreas