Notable Film Festivals cannot be edited without adding a "Category"

Trying to fix (add or delete missing or misplaced nominations) for big festivals like Berlin, Cannes, Venice..., mostly for past editions, I find it mandatory to put "Category", for example "Best Film", in order to be accepted, although before it wasn't necessary, it usually just says Palme d'Or or Golden Lion without category. One example: 1993 Venice Film Festival https://imdb.com/event/ev0000681/1993/1 19 films were nominated for the Golden Lion, 17 were listed for that award, and two for "Best Film", when I try to correct that these two films are merged with others, it is not possible without adding a Category, even though the other titles do not have it. Can you explain why this is happening? Thanks