I don't see any burnt tips or curled leaves and it looks like, in the second pic, the damage is primarily located at the bottom of the plant.
Otherwise, the plant looks nice and healthy.
It might be an under feeding issue as it looks to be at the bottom and that's generally where deficiencies will start to show.
I wouldn't increase the feed just yet, as the plant still looks lush and healthy - maybe continue with your feeding regimen for now and observe for another week to see if the problem continues and then make a decision.. Just my 2 cents.
Good Luck!