oh.. and that plant that is doing better but that stretched a lot: clearly, this is a different phenotype and she is far less advanced than her 2 sisters showing deficiencies. Look at her buds.. Give her a few weeks with same feeding while she catches up, and same issues will appear. That being said, in pic 3, we can see she is starting to show some discoloration on leaf tips, a tale sign of the beginning of a K def.
What is your growing medium? I see Soil 3% but not the rest...
like 1