I use the demo 'demo-login' and I find that:

It will only be produced on the mobile side锛宼hanks for your help!
This causes v--modal-block-scroll to be re-added to the body after modal exit.
weird.
Not only on Mobile. I triggered this (or a similar) bug with Firefox (#122).
Can confirm I'm having the same bug as well (on all platforms , Chrome and Firefox). Not doing anything fancy. It's duplicated on both closed and before-close events.
yeah, there is some handler that is executed twice. I can't really spot were the bug is >_<
I've made some changes that might fix this.
p.s. demo site currently has older version. test in your projects.