Plant issues starting mid flower

Can anyone recognize whats going on here, my ladys (indoor) are hungry or lacking something.. Older foliage starts yellowing which progresses to blotchy leaves then they dry and drop.

This happens in mid flower and comes on fast. Soiless mix / well amended

Well to me it looks like a deficiency. Deficiencies are usually the result of other things like lockout so have you checked your ph?