Is that a thrip in picture 4, or am i thripping? Check for pests real quick if u don't mind, they are really small like 0,5mm long, check under the leaves too and in the soil too next time you water if u don't mind. (5 minutes after watering go see if there is movement over the soil, like try to focus your eyes 2 or 3 cm above the soil, if stuff nearly invisible is jumping up you will know it, they are nearly invisible but are big enough for your eyes to detect the movement if your eye sight is not the same as a banana.
plants looks healthy my guy, a lot of dust on top of the leaves tho, maybe u can get a dust net for your active intake or use the one in the tent with passive intake.
They are looking good nonetheless.
Those spots can be from a drop of water or nutrient mix that stayed on the leaf and caused a burn with the light on in.
Stay lit gromwie.