Hey @PersnicketyGareth — massive thanks for sharing this! 
This tiny order-of-operations thing in Enhanced Input can cause hours of confusion — especially since it “looks right” at first glance.
We ran into a similar issue in a project recently, and your fix totally checks out. Honestly, one of those cases where a quick comment or note could save someone an entire afternoon of debugging.
And speaking of comments — one thing we’ve started doing in our team is leaving dev notes attached directly to the asset or config inside Unreal (whether it’s an IMC, a BP, or a skeletal mesh). That way, future us (or new teammates) don’t repeat the same detective work six months later 
Thanks again for dropping this fix — definitely bookmarking it, and I bet many others will too. Welcome back after 10 years, by the way! You just saved someone’s sanity.