Game or addon bug? Lockpicking doesn't respond until /reloadui

[Treadpool]

This is an odd one, curious if anyone has seen it. There is no error and I can't place when it started happening - sometime in the past week or so. When I go to lockpick a chest, my mouse can move the lockpick across the tumblers, but clicking doesn't lower them to pick the lock. It doesn't do anything. But if I /reloadui, and re-attempt it works just fine.

I have disabled all of my addons in hopes I'll find a chest soon to test. Just curious if anyone has experienced this.