SHOGUN / LSD & SPOL

Having some problems with one of the plant- Shogun. Strange dots on leaves. At first I thought it could have been caused by excess humidity, because the spots first appeared in places where some of the water condensated. I lowered the humidity since, but the spots still continue to appear. Both lower and upper leaves are affected (new leaves are affected less and the condition worsens as they mature). Leaves are affected on all sides of the plant, it looks almost like some sort of mechanical damage (like if the epidermis was scratched off from the upper part of the leaf), but some of the spots are in places where there is no contact with any other part of the plant (just checked) so I dare to think it´s something else. I also checked both the plant and the soil repeatedly for pests and found none. The spots and their surroundings also appeared to lack any fungal growth when viewed under a microscope, but I´m not really experienced with those so I can´t honestly rule them out completely (humididy has been lowered to around 40 % for cca two weeks). Since the plant grows under LED lights (cree 100W white and red chips in 80x80cm tent) I thought it might point to Ca deficiency, been adding CalMag for some time (moderate to upper-moderate doses; 0,3 to 0,8ml/L), I grow in Biobizz light mix soil, I haven´t been really adding much other nutrients (low doses of Biobizz Heaven and Activera), but it seems to have more than enough nitrogen at the same time (noticeably dark leaves), which is also mystery for me. I should note that it´s my first time growing with LEDs (long time HPS grower), I ve never experienced any problem of this sort while using HPS. The first picture shows oe of the larger spots in detail, the second one is the same spot zoomed out and the third one shows the aforementioned leaf in a whole-plant context. The following photos demonstrate how varied in size, shape and placement the damage is. Fourth, fifth and sixth picture show one of the spots that appeared in the middle of the leaf surface. Pictures 7 and 8 show what I initially suspected to be the water damage. The picture 9 shows leaf in photo no. 7 highlighted in context. I´d say the damage visible in picture no. 7 is the best representation of what I am dealing with. This is some serious Colombo-grade mystery for me. Any further advice is much appreciated. Thanks a lot for any help!