Brain Freeze and CCC not proccing on bosses?

I’ve read online resources dating back to at least early this year that Brain Freeze + CCC are supposed to proc on bosses. I just tried it against Katagawa Ball and it doesn’t seem to do so. Do I need to do a lot of damage for this to proc? Or was this nerfed/fixed in a patch?

I got CCC to work on Graveward just now so it should be still working.

find a subject you can reliably crit and use ass stop gap just in case, it always worked and should work.

It doesn’t have to do anything with damage. Brainfreeze could freeze a max level enemy on M10 with a lv. 1 gun in theory.
You just need to hit a bunch of crits in quick succession. Ideally you might wanna use a gun that has a lot of projectiles and can be fired quickly but is still fairly accurate, maybe a Maggie or something like that.
And of course you need to make sure that you aren’t taking damage, otherwise you don’t get the action skill refresh from CCC,