I fixed the problems with 18.104.22.168 by installing the latest version from this web site as Twitch didn't have 22.214.171.124 yet. Everything was looking good until I loaded my warlock. My pet health bar was way behind current, not moving, or dark (126.96.36.199 was doing this for everyone). Sometimes it would track perfectly. I just "updated" to 188.8.131.52 from the Twitch client and I am going to retest.
Before the server shut down I was able to see the initial bar behaved as it should. I will take it into an instance for more testing when then server comes back up.
There was a Monk that posted a similar issue that did NOT get the attention it required. My priest is having the same problem. Where left mouse is set to Flash Heal, Middle to Renew, and Right to Heal. Coming out of combat for a random amount of time (sometimes, enough to be frustrating), Left mouse button set to Flash Heal becomes Heal Resetting HB doesn't correct the issue, just waiting. I set Left mouse to other spells and the same happens. I even created a macro /cast Flash Heal called it FH, assigned and happened again. Enable bars at all times and Always use enabled are set. This has happened in a previous version a while back and went away. Its currently active on 184.108.40.206 (from Twitch)