Ability bars get locked after using certain abilities, it means that no ability can be used, no roll-doge, no block, no ability bar swap possible and also client side visuals show movement of the player, but other players see standing player not doing anything.
Shield assault from one hand and shield abilities causes permanent player freeze.
Take flight causes permanent freeze.
Roll-dodge causes 1-3 seconds freeze.
etc etc etc
Looks like these rapid position change abilities cause absolute desync of the players client.
Besides the terrible lags on EU servers as always, this is really critical issue. Servers performance almost the same like during Midyear Mayhem, unplayable.