Anim Montage jerks down at the start


Hello everyone!

I have created an anim montage out of an animation clip and am switching between the two in the gif above.
As you can see, whenever I select the anim montage, the model jerks down before going back up to its proper position. This problem also persists in the actual game, so if anyone has an idea about what might be causing this, please share your wisdom with me! Thanks a bunch!