These are outdoor correct? The post with grow info still isn’t quite enough but #1 they were a little young to defoliate. #2 never leave your cut foliage remain on the soil, invites pests. #3 is that 3 plants in a 5 gallon container? Outside you want closer to 20gallon per plant, though 10 should be ok per plant.
Regarding those spots, need more info regarding soil, inputs, watering schedule and ph of water. They could be a sign of pests so check the undersides of those leaves for possible intruders.
Yes, they are outdoor in a 31 gallon container.
Soil is a mix of universal, cacti, pearlite, pine bark, nothing specific for cannabis.
They were given once or twice a fertilizer (nitrogen 5,5%, phosphorous pentoxide 5%, potassium oxide 7,5%, organic carbon 4,5%, and others under 0,1%).
Ph unknown.
I checked under and on the leaves but Ive seen nothing, and nothing unusual either such as webs.
Thanks for your advice!!