Any idea what’s going on here? 2 days from healthy to this

As the title says, the plant went from healthy to this in about 2 days.

Autoflower THC bomb from bomb seeds
medium:1gal coco floraflex quick fill
Light: qb288 b spec dimmed to 175w @24”
Feed: fox farm grow big, big bloom and cal mag. PH6.0 EC1.4

plant was doing great until Saturday morning when i went into the room for the morning routine. I flushed with ph’d water and reset with ph’d/EC food to runoff. Runoff was identical to what was going in. It sat for a day or so due to harvesting duties in the other tent but there’s another auto next to it doing great so not sure what I did here. Should I bump EC up or start introducing bloom food since it’s beginning to flower? Is it stressed from the light? Defa curve ball on this one and would like to get it straightened out best I can as well are heading into flower. This is my first time growing in coco. It’s been great so far so hoping to stay on the same track! Thanks!

I also want to add that the lower foliage looks healthy. The stripping of color and associated changes seem to be starting from the top and working down. Mobile vs immobile nutrient deficiency? Thanks for patience I’m a beginner grower

I'm not saying this is the cause, but you definitely need to lift that grow bag up off of the saucer, get a riser or a diy solution. I wouldn't raise the ec, that won't help for something like this. Why did you flush with plain water? You never need to do that in coco, just run through your target PH and PPM until the media matches it. I'd start by checking the PH and PPM of the runoff to see if either is way off. Are you planning on transplanting before flower or is this the final container size? If you're planning on transplanting, that might help as well. My guess is a drainage issue.

Thanks for the reply. I thought maybe something was out of whack within the soil hence the flush. I flushed with ph’d water not plain water.
when I re fed the ph and ppm matched the runoff so ph and ppm are stable. I do not plan on transplanting as it’s an autoflower and already starting to flower. I’ll grab pot risers today to get the bags Off of the saucer