A good defoliation will bring down humidity . It looks a little overcrowded in there. Or upgrade the dehumidifier .
Low 40s rh isn't needed this early in flower I don't think . You should be good around 50 . Then bring it down towards the end if you can.
They will still flower mold free with 50 to 60 humidity as long as their is good airflow in the tent . Good luck 👍