Battle Presence is not being applied to core guards and dragonhunters while their virtue of resolve is off cooldown.
I know - they have their own resolve ticks ticking, but if you are a support firebrand with loremaster for example, with another support firebrand nearby, you will receive his battle presence ticks instead of your own resolve ticks, since he has outgoing heal bonuses and therefore his outgoing resolve ticks > your own resolve ticks.
If you are a guardian or dragon hunter though, you are stuck with your own resolve ticks until your get your resolve on cooldown... since most of the times core guards and DH's are either power or condi, then you are stuck with 70-80 heal ticks instead of the 370 or more you'd get from the support firebrand.
If I had to guess, I'd say this is hard coded by mistake because of the "triple justice" exploits ppl were pulling when loremaster was introduced, but it just doesn't seem right and is a big issue in wvw.
The Siege Turtle beast skill Hunker Down, does not trigger Invigorating Bond bonuses (Prot + Vigor), nor the regeneration given by the Rejuvenation trait. Basically, it seems it's not being treated as a Beast skill.