Baby still cries before naps after sleep training

First and foremost - I am not going to tolerate or respond to any anti CIO or sleep training responses. You do what is right for your baby and I’ll do what’s right for mine.

We have successfully sleep trained our 7 month old using a gentle version of the Ferber sleep training method. However, we are noticing that our baby continues to fight naps, sometimes crying in his crib for nearly a half hour before falling asleep. This doesn’t happen every time though. He seems tired before we put him down, but often cries before sleep unless he is nearly unconscious when we put him down. Has anyone else experienced this?