CalMag or Lightburn?

Is it only present on the sugar leaves or is it present on other leaves too?

This is burning from feeding too much.....or too often...........or both. It is not a cal/mag issue. At this stage of the cycle, it can often be attributed to never watering properly with adequate run-off each time, leading to a build up of nutrient salts in the substrate, causing the burning. Only you will know if the lack of run-off is a contributing factor. Remember too, what is showing today in the leaves is a direct reflection of what was occurring in the root zone 2-3 weeks ago. I suggest you give just plain water in normal amounts for the next 7-10 days and when you resume feeding, half to three quarters of what you were giving previously should be enough.

looks a bit overfed (very dark/lush), but could be the picture playing tricks, too. light burn could start that way with some interveinal damage, but if this is "normal" as you say, you should be changing hanging distance or light dimmer to stop this from re-occurring. That only is a negative if it is 'usual'. easy to eliminate this as a possibility.. is it occuring underneath in more shielded/shaded areas? if so, then it is not light-related i see a pistil changing rusty color, but not the cola itself. at least in the 1 pic provided.

Es muy probable que sea Calmag, mas por la etapa de floración que parece que estas. Deberias controlar los valores de EC y PH en algún runoff para ver como se encuentra el medio de cultivo y entender si es una carencia o un bloqueo de Calmag. Si el PH es bajo y el EC muy alto, tienes un bloqueo, de lo contrario si tienes el PH correcto y la EC mas baja que la de entrada, es por carencia.