Even though I don't know why it's doing that, I do know that if you animate with Blender and convert the animation with Maya, if done correctly, it's glitch free; If this would work as a workaround, just ask me, and I can give you the steps to do it
I have a laptop and I've heard the laptop version of Blender is harder to use than the PC version, I've tried it myself for a render but I couldn't quite get it. I eventually did find a fix though. I just copied 1-23 frame before adding in the 29 frame pose. It worked and it's all flowing smoothly now (I'm pretty sure this won't be a fix for all occasions). Thanks for the advice though!