I purchased the ring from a Vendor at the shrine being rebuilt, its description states it can boost the 'Channel Energy' supply by 2.
It does not, no matter where I rest or re-equip it, no extras are gained.

Another bug, or am I missing something?

Still amazed by this game though!

sadly, item boosts do not apply if you rest in town. when you rest on the map it should be fine. if not - it's bugged for you