[Fractal] Underground Facility still bugged after years

[Dark.7069]

- Invisible marker fix when?
If the group wipes and resets the boss fight, the marker becomes invisible until the boss targets someone unmarked. (This seems to be partially fixed because it used to disappear permanently and you would have to restart the entire fractal.)

- Ice Elemental random AoE damage, knockback fix when?
This one has been around for years and I'm surprised nobody has ever talked about it. This happens *every* time with the Ice Elemental boss. There is an attack that the Ice Elemental boss does; it's when he charges his attack and gains a purple "glow" effect while charging. At  the end of it, he slams the ground. There's a weird bug with this one where the player gets hit by a powerful AoE knockback at random. It can be at the start of the charging animation or half way through. It's completely random. Sometimes he will just casually walk (chase target) and do the AoE (no animation). Sometimes the slam he does at the end doesn't do anything. Basically it's impossible to predict it & dodge because there are no visible cues for it. I'm not 100% sure but I think it also ignores stability. Somehow the skill effect (damage AoE) is out of sync and triggers too early instead of when he does the slam attack which is what I presume is happening here.