[Gameplay] Sion Stackable Bug

When I was trying out the new Sion on the PBE, i found what may be a bug regarding Mejai's and Sword of the Occult. I started out with 20 stacks, died, was revived by passive, and soon died again. When i checked my stacks, they were down to 9. This issue is most likely due to his new passive. Hope this helped to point something out. Thanks.