Any guess about the cause of this points on leaf?

[MWgrower]

The first pics up top definitely look like bleaching due to some liquid being on your leaf. When you recreated it, how long did you leave the H2o2 on it? Cause it can take a few for the light from your fixture to cause the bleaching as it magnifies thru the liquid. But that pic you posted at the bottom from earlier in the cycle clearly looks like pest damage. You can tell cause the damage is from the bottom of the leaf causing mid-coloration on the top side of the leaf. I’d be willing to bet if you flipped over the leaves in in the picture up top that there’s no damage underneath. Not all insects will cause damage from the bottom of the leaf, but quite a few do