Ezra + R2

I don't know how should it be. But from my experience it seems to be 40%

Should stay 40%. It is calculated at the start.
You can see mechanics here : https://swgoh.gg/characters/ezra-bridger/ability/rushing-strike
You'll see you calculate chance to hit, and only then doing the damage.
But it's a beta version as disclaimer says. So it's 99% safe to say that if he debuffed before the first hit , it's 40% chance.

First %40 then cleanses and becomes %80 thats how it should work

"JaVCn;c-1294999" wrote:
First %40 then cleanses and becomes %80 thats how it should work

How it should work is irrelevant