Once Jaina gets 30k stacks, the Improved Ice Block still shows as Improved Ice Block instead of Ice Cold.
When activated, the button greys out but doesn’t show a cooldown.
The cooldown does show on the cursor if you try to use it again while it’s on cooldown, but not on the UI at the bottom.
Once it’s off cooldown, the button still shows as greyed out, so the player never knows whether or not they’re able to use it until they press the hotkey for it.