Look at the leaf with the white powder look to it. It's right above your spotty one. Take a very close look at that with a loupe. It looks like you might have Powdery Mildew.
It looks like you have a bit of a P and mild Mg def. But make sure that's not PM and if it is treat it. I use Marrone Regalia for PM.
You have a keen eye curious2garden thank you. I will check with a loupe when the lights come on at 4. I hope that it’s not powdery mildew, however I am having some difficulty keeping the humidity below 50% let alone the 40% that I’d like as lately the relative humidity has been over 80% most days. I have a 90x50x160 Growlush tent that I unfortunately have to keep in a closet. I have a dehumidifier inside the tent in addition to an exhaust fan pulling through a carbon filter in addition to 2 oscillating fans and the exhaust is running out of the closet which is near to a window. I need to get some fresh external air into the space however I’m not sure how to go about that one. Again thank you, much appreciated