extra life support rune in extra life mode

[Penitent One]

I am about to complete TAG 1 with extra life mode on nightmare, and i noticed that the game says in this mode that support rune which gives back an extra life if you kill a demon who took that life from you fast is disabled and also in nightmare mode too.
Pretty clear okay, well what is not that clear i did equip that rune for the very first time when i started a new save and get my hands on the first rune because, you know extra life mode is hard to complete with 5 or more and ♥♥♥♥ it i can get back a life is helping me a lot
and watch this, i did lost a life and killed that hellknight within the time limit then i got back that life ,after this i failed at the blood swamps badly so i restarted the whole dlc but this time i was about hmm what are those 2 other runes
then i noticed the messege the the rune i used before is inactive in this mode i was confused because, what bro i just did use that rune before and worked perferctly so i did chose that again and booom what that time didn't worked
and after that okay maybe it was a glitch or something, i did changed go on and continue the progress
i restarted again the save because lost to many lives (i love this so much )
and i equipped that rune again and that time it worked again
so what the hell about this rune? one time ok and other is not ? i mean in other save file not in a row, i know if one time i use a run it needs a cooldown so is not about "yo man you didn't know they have a cooldown" i know thats is why very strange this isn't supposed to happen not even once
whats with these extra lifes? should i use it or live without it

[CzechKronner]

It's not supposed to be used in Extra Life mode, Just ignore it and do it legit.