some claw and a little glossy, if pic not deceving me. So, it's overfed a bit. This brings possibility of p/k locking out Ca/Mg. Check pH too.
9 weeks into flower is little concern, but can adjust next time, so it's good to figure this stuff out for posterity.
Senescence will happen. the plant dies at end of year. This can also be a factor here.
As i look through diary, less certain about the gloss... must jsut be angle. Ca/Mg symptoms take a long time to present themselves (useful tidbit, not sure about timetable if locked out, though.. that i would guess is more closely coinciding with initial problem). the fact it took a long time is good too.. this will require a small adjustment to nute mix or regular feeding schedule.
people like to boost p/k in flower, but that'll cause Ca/Mg problems like clockwork, too. in a soilless substrte and with hard wter i only need 80ppm Mg and 100ppm Ca in my mix to avoid deficiencies, if tht helps. with ro, you'll need more, with better tap water, still need more. Soil is an unknown as it has some stuff already, but late in grow potentiall all from fertilizer.