Looking at the setup and the photo, those upward-curling leaf tips combined with the lighter lime/yellowish hue point pretty clearly toward a combination of mild nutrient burn (nitrogen/hot spot) and some light stress given that 30 cm distance at 80% intensity.
* The Light Factor: At 30 cm with the dimmer at 80%, depending on the specific LED fixture, that's getting pretty intense for day 30 of bloom, which can cause the leaf margins to taco or curl upward as the plant tries to transpire faster than it can keep up.
* The Nutrient Angle: The tip burn (clawing/crisping right at the very ends) usually flags a touch of excess salts or a heavy feed. Since you're mid-bloom, they're hungry, but if your medium is getting a bit hot or concentrated, it'll show up right on those tips.
* Next Steps: I’d back the light off a bit—either raise it a few centimeters or dial the dimmer down to around 60–70% to give her a breather—and make sure your next watering is plain pH-balanced water to help flush out any built-up salts in the root zone.