Can your plant have not enough stretch?

Magnesium and micro nute deficiencies I believe will cause short neck syndrome (just coined that). Had that problem under leds

Your plants look like they are being overfed. This can cause deficiencies via nute lockout. What medium are you growing in?

Plants are in dwc with hydroton medium. Could be a lockout. Have not had to top up the water on this plant much. One of the leaves is showing tip burn. Will try and pull some water out and add fresh ph water. That should lower nutes a little.