WowAce

I've got IceHUD set to 25% alpha when OOC and not full, and 0% alpha when OOC. However, I've noticed that both the player health bar and the pet health bar will sometimes fill to full and not disappear, while every other bar does. Sometimes when I log into WoW I can see the full pet health bar and no other bars as well.

I haven't seen this happen. If you can tell me specific circumstances that cause the problem, I can look into it.

Hey sorry for the late reply, was on travel.

As far as specific circumstances go, it seems to mostly happen after leaving combat and your/your pet's health naturally ticks back up to 100%. More often than not the health bar won't fade away. I wasn't able to discern anything more specific than that. I also tried dismissing my pet to see if that affected the player health bar but it still happened.

Here's an example: https://gfycat.com/RigidAngelicCuckoo

You can see the bars appear as I enter combat, and the energy bars for both the player and the pet properly fade, but both health bars remain visible once filled up 100%. Whenever this happens the bars will remain visible until I target something and then untarget it.

 I'm not sure what to say about that. I've got my transparency settings almost the same as you describe and have never seen this before. I'll keep an eye out for it.