Guild Wars 2

It’s been a couple of days now that I don’t get any
bonus XP when using a XP booster and/or food that
gives bonus XP.

There’s definitely something wrong here.
In most cases I pop the booster and I get the same if not less xp than without it.
Can somebody check this out?
The xp numbers I’m getting are all over the place.
A few random examples.
Tested on a lvl 80 Thief,with and without a ‘+50% XP from kills’ booster,and no other booster/food active.

Marsh Drake (Lvl 46 Bloodtide Coast)

Without the booster: 316 base+594 bonus = 910 xp

With the booster:447 base+354 bonus = 801 xp
———————————————————————————————————-
Basilisk (Lvl 46 Bloodtide Coast)

Without the booster:315 base+741 bonus = 1056 xp

With the booster:447 base+390 bonus = 837 xp
—————————————————————————————————————
Dolyak (Lvl 80 Frostgorge Sound)

Without the booster:401 base+941 bonus = 1342 xp

With the booster:568 base + 179 bonus = 747 xp
———————————————————————————————————-
Grawl (Lvl 80 Frostgorge Sound)

Without the booster:401 base+56 bonus = 457 xp

With the booster:568 base+0 bonus = 568 xp.
———————————————————————————————————

In most cases it’s less xp per kill with the booster on than without it!
In Verdrant Brink yesterday,base xp gains from kills with and without
the booster were exactly the same,but with the booster on I got no bonus
xp from any kill,so overall I was gaining more xp whithout it.