Ok I have narrowed down how to recreate it.
Of course it is the portal.
Using Temerity with Zir’s secondary, main is Grigoire’s power.
Works fine.
Portal to town.
Step back through it to where you were.
And now you will see the barrier is stuck in single digits unable to grow when you predictably attack things with your core and boss power.
Now please fix it.
I can actually use it now again that I know WHY it is happening, but taking my pants off (and putting them back on) when I show up to a fight seems a little excessive. 
Also not sure if it matters, but I am using the new BP portal the fancier one from the paid section.