Hey there so i agree with the look of mag deficiency, whenever the leaves have that margin discoloration (it always looks like a grid to me) i think mag. Its often with other deficiencies too and low ph. If your roots are incapable of absorbing it i would suggest doing a foliar application (close to lights out though) like you're doing...but maybe try epsom salt rather than an actual calmag sup, as E.S is mostly just magnesium.
I see you dont have a ph listed, if ypu don't have a pen maybe you can get your local water report to get the starting ph? I think mag does best 6.5-7. Finding a very finely ground dolomite lime to add to the soil may be the best option if ph is unknown as it helps to buffer the soils ph. I
hope you find your troubles and can fix them. βοΈ I know ph can be a nightmare, but it definitely helps rule out a lot of problems. Happy growing