ACE Seeds Ace Mix

That is your led grow light bleaching the top of bud back off immediately. Or it will be worse. Always check your led manufacturer recommendation for hanging distance very important. And don't exceed the max. If ur at Max back off to the min for flowering stage.

Two possibilities one you have light bleaching the tips of your buds or choice 2 you have pure trichome over trichome density on the tips of your buds https://news.californialightworks.com/how_are_white_tips_formed_on_cannabis_buds/ The plant produces trichomes to protect itself from damage from the sun. Look at it with a 40x led lighted jewelers loupe (Amazon.com) You'll have to decide which it is when you fire up the tip of that bud.👌

I had the same exact thing happen when I had my high-end LEDs a little too close to one of my plants. It was literally the light bleaching the chlorophyll from the bud/leaves. This is bad news as bleached buds have significantly lower thc content and it causes stress to the plant. Back off the light from your plants by at least 6 inches and see if it continues. If it does then just back off more. It takes a bit of trial and error to find a proper height for your lights. You can always try to go by manufacturer recommendations, but I've noticed you can usually get a little close than that. If you want to just be safe it might be a good idea to back off to the manufacturers recommended height.