[5.4] Character using motion matching will continually animate in builds

As the title suggests, the character using motion matching will continue to move in all builds and animate, without input. Its very strange. See the video below for a clip of the supposed bug.

After a bit of sleuthing and rebuilding, I’ve noticed that a fresh gameplay anim sample project build does not display this behaviour and i’ve narrowed it down to a custom parkour anim BP.