WowAce

 There is an issue with State Configuration of being in Cat Form, but not having the bar configured to be used when in Cat Form.

The issue occurs very frequently (over 50% of the time) when using a macro to cast Moonfire and Tiger's Fury.  When used without the Feral talent Lunar Inspiration (Talent:1/3), the expected result should be that Moonfire being casted forces you out of Cat Form then Tiger's Fury immediately forces you back in Cat Form.  The in-game mechanics seem to work perfectly fine, casting Moonfire (and applying the debuff to the target and momentarily putting you in no form), and then casting Tiger's Fury (giving you the buff, energy, and putting you in Cat Form).  The bartender bar however, will get stuck on the no form bar and does not re-update to the Cat Form bar.

The macro used:

/cast [notalent:1/3] Moonfire
/cast Tiger's Fury

While there may be other unintended results when using the macro improperly, (such as if pressed while Tiger's Fury is off CD, making you just cast Moonfire and forcing you to no form or pressing it mid GCD making you skip the Moonfire part and just cast Tiger's fury) but the issue remains that sometimes the abilities function properly, Casting Moonfire, Forcing you out of Cat, Casting Tiger's Fury, and Forcing you into Cat, but bartender is still showing the no form bar.

Some tests I tried:

Without spamming the ability (macro doesn't activate multiple times and no form abilities are attempted to be cast during the split second the bar updates to no form) it basically never bugs.  You will pretty much always get your cat form bar back.

With spamming the ability, it happens much more often.  (either the macro is activating multiple times or a no form ability is attempting to be casting mid-GCD which should not trigger anything since you are GCD locked)  Either way, the issue is that it leaves me in cat form with no form (default) bars. 

I don't know how the state configuration works, but a temporary "fix" might be to allow a command to update or force a bar to change state to macro into the Moonfire + Tiger's Fury macro.  Something like /bt Bar1 StanceConfiguration Update or something.  My guess is that the code is meant to change the bar when the Form/State is first changed and not a constant check and that the "fix" of constantly checking the form would be a higher resource hog.