There’s an August 2020 post on this as well, but the trait “living flame” seems to be doing 0 damage consistently. I went through the patch notes around the time and didn’t see any mention of it having been fixed, so figured I’d post about it.
On live version (1.0.4) and windows
I’m not sure if this is due to the burn being placed by pyro’s perk or just the perk not working in general - but so far just doesn’t seem to deal any damage.