khaki Cannot Walk

[ChickenCanoe]

They may have been started on layer feed too early. I think Khakis start laying around 20 weeks (depending on time of year-perhaps later in autumn).
The difference in layer feed is the calcium percentage. That is to replace the calcium lost when building egg shells. There really isn't anything about layer feed that induces laying.
Scratch and Peck layer is about 4.25% calcium. The instructions on the bag say to begin feeding at 20 weeks. If your birds are now 16 weeks and you started feeding it 3 weeks ago, that is starting at 13 weeks and WAY too early.

 

[Miss Lydia]

I'd offer an all flock it's is the best for water fowl if you can't buy a specific water fowl feed. Even layers can be on it and just put out oyster shell on the side. That's great you got the B complex.