about the critical damage current lv cap affects lower cap mobs

[bladestar7]

hi , was wondering if the critical damage cap affects is bugged or it is sopose to work that way (the crit damage description is misleading then) where a 93 cap player (280% in 93 cap crit damage) is not dealing full 300% crit damage to lv 90 boss/mobs which he should be doing since he is sopose to be doing 300% crit damage already for 90 cap
i did a little testing before DN SEA closed for upcoming migration
https://www.youtube.com/watch?v=I61IhdyYvCw&t=1s