Weird interpolation change

[WatchMotion]

Hi all, I'm dealing with a problem I've only encountered once before and couldn't figure out what caused it. Any new keyframes are interpolating as if they were step keyframes and not smooth (they're set as smooth, screenshot attached). This occurred after I duplicated a rig's main art folder which is a subfolder of the bone layer itself. Interpolation was working for a while and then it started this stepping thing. Any idea why this happening?

[synthsin75]

I'd have to see a file.