On Fire CDR Bug

(This bug applies to the new Nexus Blitz mode) When on fire, you gain +20% CDR. This can push you over 40% cdr by default. When I was on fire, I bought a Lost Chapter and dropped from 40% CDR to 30% cdr, which leads me to presume that buying an item after the on-fire eliminates the cdr buff. After getting another kill, I bumped back up to 50% cdr, which makes me presume that the game reaffirms the on-fire, and that this is based on a "which was applied last" system.

But I'd imagine you're not supposed to drop from 40% to 30% cdr at 'all'.