what am i doing wrong?

[Symbiant]

Before a tank swap I typically pop FoF. Then I que up savage blade / voke / sprits /savage / RoH / CoS. If I can't que savage I just FoF / Spirits / solo RoH / CoS then do my typical rotation. If healers / dps are snapping hate right after your voke then it seems the other tank does not have a solid lock to begin with. Now if you took hate from the other tank and then lose it a couple mins later... well that's something on your end. Make sure you have Shield Oath up. Some of us like to squeeze the extra dps and switch to Sword Oath when not tanking the boss and sometimes people forget to switch back. Either way you should not lose hate that fast.

[RhazeCain]

Most things covered already, but I didn't see a mention of communication yet. By telling people, especially the other tank, when Provoke is happening you get at least a chance of them knowing to back off for a few secs.

This can be a macro that puts something in /party chat at same time as Provoke, or something you say on voice chat, or both. There's a reason every successful endgame group uses voice chat, and this is part of it.