I am experiencing similar issues. I spent a lot of time assigning classes to all the elements of my model in Vectorworks (v2021), however I don't seem to be able to select items using the class filter, once they have been imported into Dataprep. I can't seem to use 'Object name' either (the names attributed by dataprep to the individual actors relate partly to the classes I specified, but I type 'wall' and it's not recognised. Even if I type the whole thing in, it is not recognised). Is there a way I should be organising my file, before export, to make editing in Dataprep easier?