@Tim_Shannon : I took a look at your new file, and here are a couple of comments 
!. Weight Painting : I looked at the weight painting for the bone for the body (Bone) and for the bones where the legs attach to the body(Bone.001 and Bone.022). See first image below. The body is 100% weighted (red colour) but the leg bones are not - yellow, green and blue. And examine all the weight painting for all of the leg bones - not great. This will not help your animation.
2. Chain Length ; I also looked at the IK bones, and I see the impact of the IK bones have a zero chain length - that means that any one IK bone will influence all other bones in the rig. That is not right. (Second image below.)
I don’t use the gtlf exporter - but do not understand why it works given the above.
I won’t be around for a while because of family health problems, so good luck.
Stay Safe Tim, gryff
