Grace Period gets broken by Autoexertion-supported Warcries

Autoexertion breaks the grace period, and of course I had to discover this interaction during the Act 9 Boss of the gauntlet...
I post this here, because I don't think that it makes sense that it works like that, but that might not be considered a proper "bug"

https://www.twitch.tv/les_doseurs/clip/SpunkyNurturingDurianAMPEnergyCherry-nJTzDaUOieKcKJpC

Not a bug at all, just realised that the grace period had a timer and it ran out.
Never played around it before --
Nothing to see here