Medium Zakum seal/dispel glitch

Description of the bug: Sometimes when Zakum seals, the seal gets stuck on my Bishop and can't be dispelled. During that, the only skill I can use is Dispel.

What is supposed to happen?: Usually, Zakum seals, Bishop dispels, everybody goes back to what they are doing. However, there are a few times when I couldn't dispel seal from myself. Everyone else gets dispelled, but the seal remains on me, the Bishop. Then, no matter how many times I try to dispel, I can't dispel the seal on me until it either times out, or Zakum applies a new seal. While in that sealed state, I can't heal. The only skill I can use is Dispel.

Where did you find and/or notice this bug?: During the past two Zakum runs I have been on as Alke, a Bishop. Eh, can't remember exact time and date, though.

A step-by-step guide to re-producing this bug (optional): This seems to only happen when I dispel at some exact timing down to the millisecond. When Zakum shows the seal triangle, I press dispel, and sometimes, seal remains stuck.

Extra information (optional): This could be happening because I am in Australia - long Internet route and ping. Sometimes I noticed that when I try to dispel quickly, everyone else in the party gets dispel but I remain sealed. Then I have to dispel again to use other skills like heal. This made me think that seal goes into effect at different times for different players as it seemed like I used dispel when seal had affected them, but not me just yet = my effect time was later than others'. Hence, I believe that this bug happen when I use dispel at some sort of timing that makes the "effect" command of "seal" and "dispel" runs at the same time as my "seal" effect is a little delayed.