Overflowing energy key passive stops working after one town trip

I’m playing a cracking energy sorcerer and recently I tried switching my off-hand weapon to Okun’s Catalyst. Every time I log in and go out fighting (say Azmodan) it works great, but after one town trip the key passive “overflowing energy” stops reducing shock skill cooldowns. The damage numbers on Azmodan look lower too, but that might just be my imagination.

Relogging in seems to temporarily eliminate the bug for the first outing, but as soon as I return to town the bug reappears.

I tried switching to my legendary off-hand, and the bug doesn’t appear then so it must be related to the Okun’s catalyst since that’s the only gear I changed.