Electrocute stuck at 99% on some bosses

Recent example is Tor Gul the Defiler: the first build up of electrocute got to 99%, I continued to attack through 6 of his attacks, THEN he got stunned from the electrocute. I believe it was well over 30 seconds he stayed at 99% and didn't stun.

Is this expected behavior? Feels quite bad that bosses can effectively "ignore" electrocute build up in some cases.

Another example is the Count in Act 1, though more annoying is him becoming invincible while he gets to do his dialog, yet still gets to attack the player. Can he not be downed while this dialog is occuring? (Between his two phases)

Cheers!

Yeah, just had the same issue with the map version of this boss (Zar Wali, The Bone Tyrant). Stuck at 99% Freeze and 99% Electrocute and neither went higher while hitting him a bunch.

Map was 34% delirious.

#Bug Report No.: 2.013.172.405

this happenes to me with zar wali and other bosses just using mace strike building up stun regular.

I've had this several times today with freeze on bosses and with rares. This is usually on the second time of freezing them.
Sometimes it lasts a few seconds and resolves itself.
Sometimes it goes on for many seconds and doesn't resolve itself.
Some have suggested it is to do with them being in an 'animation' mode, but it's not that (especially since it happens with rares, not just bosses with stages/modes/etc).
I'm playing a frost wolf druid.