Hi there! Welcome to the forum.
So for starters, at least in the final photo, this looks a whole lot like potassium deficiency. I think that may track, as it looks like that plant is flowering or just beginning to flower. They definitely start wanting less nitrogen and more potassium & phosphorus as they transition and flower.
Secondly, I highly recommend filling out a “support ticket” with the information below copy & pasted and completed to the best of your ability. This information will help your fellow growers diagnose more accurately and/or identify other weaknesses before they cause problems.
COPY/PASTE the below list into your forum post.
Answer these simple questions the best you can.
If you do not know, or do not use something; Just say so; Or post
NA (non applicable)
-What strain, Seed bank, or bag seed (photo or auto)
-Age of plant/what week of flower
-Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF
-Vessels: Pots, Grow beds, Buckets, fabric pots
-PH and TDS of Water, Solution, runoff (if Applicable)
-PPM/TDS or EC of nutrient solution if applicable
-Method used to measure PH and TDS
-Indoor or Outdoor if indoor, size of grow space
-Light system LED, MH/HPS/CMH/Fluorescents, or other
-Actual wattage draw of lights
-Current Light Schedule
-Temps; Day, Night
-Humidity; Day, Night
-Ventilation system; Yes, No, Size
-AC, Humidifier, De-humidifier,
-Co2; Yes, No
Any other info: