Q:
Is the Master's Bond trait ability bugged?
What’s likely happening is you’re walking into an area where you downscale so the stat bonus also adjusts appropriately.
As their mother, I have to grant them their wish. – Forever Fyonna
Nope, I am in the same area killing the same mobs. I have also posted a thread in the game bug section after Anet verified this as a bug through my ticket. You can also try this yourself. I have also attached a video in the other thread.
This is probably a prelude to a nerf/fix to the trait. It is (was), quite frankly, OP at lower levels because it gave the pet a flat +8 to each of its stats. With a limit of 25 stacks, that was +200, which was pretty OP when your pet’s base stats were 100-400.
It sounds like they’re tweaking it to scale with your pet’s level, which if done properly would really help the trait out. Right now it becomes close to worthless by about level 60. The “pet swap and lose stacks when you get wet” bug meant the benefit of the trait wasn’t worth the trouble it took to maintain those 25 stacks. Hopefully they’re planning to beef it up a bit at the high levels, not just nerf it at the low levels.