Meenlock fight bugged

[Komrade Kermit]

Without any spoilers, I'm fighting some Meenlocks and the saving throw for their fear aura appears to be opposite. When I succeed the saving throw, my characters are feared, but when I "fail" the saving throw, my characters aren't feared. Also, I've tried casting Daylight, Dancing Lights, various Radiant effects, etc but they don't seem to be affecting the creatures when bright light should be giving them disadvantage and preventing some of their spells.

Hopefully this gets fixed soon because this bug means the fight is paradoxically harder with a paladin and cleric aboard since they mean I'm more likely to succeed and thus "fail" the saving throws.