I cannot drink from my Olroth's Resolve life flask

I cannot drink from my Olroth's Resolve life flask, presumably because I'm chaos-inoculated, and therefore always at full life (or dead).

Still, this feels like a completely arbitrary limitation. I get why regular life flasks are only "drinkable" when injured to limit waste, but in this instance, I want to make use of the "excess life recovery added as guard for 10 seconds" modifier.

There is no logical reason why a character couldn't drink a life flask at full life. If the worry is about beginners using it wrong, a "Flask consumption restriction" entry in the game options would be appreciated.