Don't really have that much experience with it, but it doesn't seem contradictory or surprising to me.
Humble use would be referring to oneself, derogatory use would be referring to someone else. I mean, that's kind of the whole point of humble language, it explicitly lowers the status of the user when referring to themself.
Though, I just noticed you said "the third entry was marked both humble (sonkeigo)"
It's marked kenjougo. Sonkeigo is honorific language, elevating the listener, which would indeed be a bit strange for it to be both, but maybe you just flipped sonkeigo and kenjougo in your head for a moment.
Yeah sorry about that
Derogatory but Humble
I searched for the word 風情 and the third entry was marked both humble (sonkeigo) and derogatory. Can someone explain the humble context of the meaning