can you check EC you feed and EC of your drain ?
your containers are big, your plants to, they are in since 45 days or so
they are maybe only hungry
but try check the EC in and out to be sure
do you have big drain ? I dont know much about the perlite parameter, ut with such big pots i would do little or medium flush once a week and multiple "not so light" feedings a day
ww is old strain oldy goldy shit
still check for insects, because spots on leafs are very often sign of the beasts... lol uncool i know...
my 2 cents