Let me explain, when I want to add two books of efficiency 5 to get one of efficiency 6 I can't, I mean in creative if I get the book efficiency 6 even the 10 which is the max.
In addition, the debug option is not activated even though it is set to true, I have already tried to deactivate it and activate it again, but it does not work.
Could you help me, please.

im sry if my english is a shit, im doing my best to translate, i speak spanish.
Eficiencia is efficience but in spanish

the title should sound "i cant combine echantments over its cap"
like i got the same problem weird enough so like that i got books with fortune 5 for example but when i try to apply them to a item, the previewed result goes down to vanilla level with fortune 3