some kind of deficiency?

It does look like an overall deficiency ( main stuff NPK + Ca+Mg+S i would say, possibly micros too). Might be due to direct problem (underfed) or indirectly caused nutrient intake issues by wrong ph or underwatering. A diary or some more information would help to solve this, without its fishing in the dark. Hope this helps anyways, gl.

This could be from a little too many nutrients i believe. and overwatering will make the tips droop along with too much nitrogen. your plant is not showing the other signs of too much N Which is very dark almost black leaves. Changes in humidity can make the leaves do funny things. This looks to be more environmentally caused but i can say for sure