It's due to there being an animation delay. So they want you to slowly carry out the animation, then the effect is applied at the point in the animation it's "logical" to. This process has to get permission from the server and these exchanges take time (ping). Then you can't press another ability until the previous one has done its thing.
The argument many of us would make, is effect should be independent of animation (instantaneous) and the animation should not be given such priority as to not be interruptable by another ability. This would support gameplay over animation because gameplay should have a certain (reasonable) degree of priority over animations and lore.
I can double weave with 170 ping but it's hit and miss and depends on the ability and its specific animation delay. SE has actually made some animations shorter and act faster than they used to and when they have done this it's made them easier to double weave. So it may benefit you to find which specific abilities have the shortest animation delays and try to double weave those, then just single weave the very delayed ones.
We have tried to tell them. We've posted about it. Bug reports have been submitted. It's been common knowledge among the English community for most of the game's history.Is SqEx even aware of this?
But the truth is, I don't think they understand. There is a language barrier and I think they just don't understand the issue or that it's a major problem that, quite universally, almost everyone wishes wasn't a thing.
I can see it being addressed someday but it will probably be completely at random. They typically do Quality of Life fixes in major patches and they suddenly fix things that have been a problem for 10 years out of the blue, as if they just discovered it and players fold their arms and think "you are addressing this NOW?!"When will this be adressed or at least acknowledged?