Solved
something is wrong with the infiltrator and the vanguard in multiplayer...
first of all the stealth cloak on the infiltrator seems to be completely useless... every enemy still shoots me no matter how far away they are... second the vanguards spells are totally different f...
Enemies can still hear you while cloaked and shoot at the last position they saw / heard you.
The stagger ability is depending on the force of your charge. So, if you didn't skill the power-bonus in the passive ability tree and / or left out force-bonuses of charge it can happen that enemies stagger less often, especially on higher difficulties like Gold or Platinum, where the stagger-threshold is higher.
