ES recharge treats Frost Shield's drain as damage, interrupting it, which Wicked Ward can prevent

Frost Shield removes/disables recharge while draining energy shield for its effect. When the effect ends, recharge needs time to start; it was interrupted.

Energy shield recharge isn't supposed to be interrupted by non-damage loss. If Frost Shield is an intentional exception, then this interruption shouldn't be preventable by Wicked Ward, which is specific for interruption 'by damage'.

Demonstration (youtube)

Bug reference 3.360.254.732

(Frost Shield isn't actually damage, it can't be mitigated or anything.)