I have water that runs through a filter system, and always phd. Usually every second day for flowering a veg? But some plants go 3 days depending on moisture in soil.
that's what i did and it seemed to help a little but then it was pretty late in the game by then. i took it to a sink and tried my best to get like 2 pots worth of plain water through it. just maybe that could be it. if you feed every time and not sure if you feed a lot or not then you might try it and then wait some days before watering again I'm really not sure but just giving you my thought. also did you look for bugs?
I think they might look over watered. another thought if so is plants don't all drink at the same rate. so if you water them all at the same time the ones that are good might be ok with that frequency of watering but these 2 might need more time between watering. not sure if you thought of that but that's another thing.