Hydroponic strawberry leaf problem

[Bazoon]

Good day!
I have a small strawberry plantation in my wardrobe. Growing under LED lights in a rockwool substrate (Grodan).
I've planted seeds in January and now I have 3 plants (2 closest a the biggest and the right far one is smaller - had problems with nutrition since the beginning), 4th place is filled with a recently planted stock.
For a long time I have the same problem - leaf deformation, and leaf tips necrosic. Some leafes looks better, some worser.

It looks like a potassium deficite, but I've recently changed nutrition for flowering with like 1.5 times more potassium in it and nothing changed. Now using NPK 188/82/291, for vegetation it was - 205/65/184, giving about 1.8EC atm.
Trying to keep PH of water at about 5.7-5.8, but not sure how is it going on on inside rockwool.
Any ideas what to do?

Some more photos:

[JONA]

Hi Bazoon.
Have you considered Calcium Deficiency ?
This leaf wrinkling is one sign of this problem.

[Bazoon]

Hey, JONA, thanks for your reply!
Well I suppose I have. Either calcium deficiency or block (caused by PH or m8b high potassium levels in latest nutrition set).
Is there any way to measure PH inside rockwool substrate? I keep solution PH at about 5.6-5.8, but things can be different inside a substrate...
Finally I changed a solution to formula with less potassium (~170) and more calcium (~240) and 1.5EC to fix the problems.
Will try to keep in touch and m8b will continue posting some kind of report here, if it is interesting to anyone