I find it strange, you are pH'ing to 5.8-5.9, which seems low to me for soil, then getting 7.5. I was under the impression organic soil didn't need to be pH'ed. Seems upping it is doing more harm than good.
By chance, have you tried watering a cup full of soil pH'ing like you have been, then monitoring pH from there? I wonder how long it takes to jump to 7.5...maybe pH up is not such a great idea eh.
Feeding @ 5.8 for a soil pH of 7.5. Why not feed @ pH 5, to bring it down?
Please don't do what I'm saying, unless it's a confirmed solution.
Good luck man. Hope it gets sorted.
By chance, have you tried watering a cup full of soil pH'ing like you have been, then monitoring pH from there? I wonder how long it takes to jump to 7.5...maybe pH up is not such a great idea eh.
Feeding @ 5.8 for a soil pH of 7.5. Why not feed @ pH 5, to bring it down?
Please don't do what I'm saying, unless it's a confirmed solution.
Good luck man. Hope it gets sorted.