ignore what the first coupel sets of real leaves show over time.. some blemishes are normal.
the little spots -- if not glistening around outside ('honeydew' is used to describe it), then it could be a bug, but i think these are just some blemishes. easy enough to figure out.. inspect under leaves and look for thrips and such.
you are probably giving more than 20dli.. if you used a phone app to measure this, it did a poor job. a phone's camera cannot measure photon/s.. it is not a quantum meter in any way shape or form.
less humidity will be good.. a circulation fan does not lower humidity.. you must extract it out of that area (may not be possible if ambient RH is high), or use a dehumidifier. Raising temp can also increase VPD, but i wouldnt' go higher than 30C
when operating at warmer temps, make sure you aren't hitting dewpoint when lights go off and temps drop.