Newbie here.
Working as intended. Yes, really.
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Midnight Mayhem
That is one of the problems by the culling issue. This is supposedly going to be fixed in the future.
If you have the thief on target, I believe the best way to hurt them is to use channeled attack because the channeling continues even after he stealth.
If you do not have him on target, what you do is you AoE the area where you think the thief is. Most thief are squishy by comparison to other professions. If you hurt them, they’ll likely go away (or die).
If there are friendly NPCs nearby, run to them if you can. NPCs are not affected by culling and you can tell where the thief is by following the NPC actions.
If you can’t see the enemy yet, you can still target them by pressing TAB or clicking whever the bullets seem to come from. They can still be hit while stealthed so try to force them a location (immobilize, stun, etc) right before they stealth and aoe that location when they go invis. That helps against the “noobier” thieves out there.
There are more tips/tricks though. The NPC one posted above is a good example.
Just try to figure out why thieves get to kill you so easily and then try to come up with something to counter that.
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