I don't think it is lockout of any nutes... unless there is a serious PH issue!
Lockout occurs when PH is not normal! Can go both ways!
Here is a lockout graph (a must know for hydro but not really a big deal with GOOD soil)
View attachment 2472916
Good soil is around 6-6.5 PH - IMO.. What nature provides through seasons (outdoors) must be replicated indoors!