BUG new burn mastery (offensive tree the last right one)

the last masterie on the offensive tree the right one is kinda bugged. It seems to deside rather randomly if it applies dmg or not it says: it would burn 1,5 secs for .... dmg on each (single targed) dmg applying ability. the bug is: brands passive does trigger it.... and that like 3 times (and as far as i know brands passive is not even an ability but a passive...) while fizz w skill doesn't trigger it.... and it actually should since it is a skill

it would be fine if either only skills or any dmg trigger it but not some random things randomly and pls write that in the description.... so annyoing when some descriptions can mean like anything.....

it would be not supprising if that mastery is bugged on multible skills and champs if you know any other examples pls write them here i have none in mind at the moment