pH seems to high

Hey Dannyboy! You're growing in Coco, Buffered, and triple-washed by AC Infinity, so that's not the problem. Black gold, sphagnum peat moss, nice mixture, moisture retention, and aeration. let's seeeeeeee....... Pots sitting directly on the floor, potential oxygen deadspots, have them raised to some degree; Dollar Store has cheap, quick solutions. Too much moisture being held by the leaf, 80F will feel like 77F internally, at 65% rh it's just too moist, overnight, probably going up to 75%+. I would get your canopy to 85-86°F ambient. During the day, you can let your rh go up to 60-65% optimizing the VPD, but at night, you keep it in the 45-55% range. There is no such thing as too much water, only water that sits too long in one place. Tips on your plant look to have very slight yellow tips, normally I'd associate that with a high salt concentration within your medium, causing osmotic stress, but your metre reads 0.3ms/cm. I'd say it's more 1.6-1.7ms/cm based on visual appearance. High salinity in the soil can interfere with the plant's ability to absorb calcium, which is essential for various cellular processes, including membrane function, cell wall extension, and stress recovery. Either the EC is too high in medium (at capacity) or the concentration of concentrated fertilizer was not watered down enough and remained at a toxic level, causing mild burns. You put in your diary that you fed a full balanced fertilizer, but no description as to what exactly it was. It's hard to tell from pics, but I can't make out if I see possible nitrogen dark green or if your leaf just got wet and caught the light wrong. There is a lot of organic stuff going on in your medium with the peat moss and bark, which really helps to know what type of nitrogen you fed. Right now, I'd just dry things up a bit, warm a little to encourage more evaporation, keep the air flowing in and out, and keep water moving too. Air outside the leaf is too moist; there is not enough space for more moisture. At 80%rh, stomata close entirely. VPD for days is great but if you don't get it back down overnight and control the flow of moisture, it leads to eventual same old problems, week 3-4 flower. Gluck m8.