Guild Wars 2

Under Firearms 8, the Juggernaut trait reads: “You gain toughness while wielding a flamethrower.” and follows with Juggernaut: +200 Toughness

However, it simply does not add the Toughness unless you already have a boost adding Toughness. For example, it works in WvW because most of the time you have the +stats bloodlust boost.

See here for details: https://forum-en.gw2archive.eu/forum/professions/engineer/Flamethrower-Juggernaut-Trait-Bug/first

Putting on Rune of the Dolyak, for example, and adjusting traits doesn’t seem to activate it in SPvP. Toggling the kit on/off in various circumstances does not activate the boost.

The engi trait deadly mixture supposed to boost flamethrower damage by 15% does not work either in actually reduces damage

I just took the flamethrower to the test dummies and cannot confirm that: in fact I do see nearly a 15% increase in DPS, so Deadly Mixtures is either fixed or was never broken.