Having issues with IK when standing still during idle animations, Game Animation Sample

I have a custom character I’m using in the Game Animation Sample (This is not the issue as my problem happens even on the UEFN Sandbox Character).

I have an animation in which the character stretches upwards, going on tip-toes and then settles back down. It works fine in the Skeletal Mesh and the Retarget screens. The character’s toes stay on the ground, bending correctly and the char stretches upwards (Pic 1)

However, when the animation blueprint (ABP_SandboxCharacter, unmodified from Game Animation Sample) takes over, the character’s feet now lift off the ground (Pic 2).

What’s going on? How can I fix this? IK works normally otherwise, character’s feet find the floor on slopes, etc.

Help! Please! Thanks!