Need an improvment on the animation theme

1. When the group is changed, the browser restarts. That is how it should be?
2. When adding a group via "Add new group", the previous current group is deleted. What am I doing wrong?

Thank you for starting work on this add-on. Successes. Surprised that so few reviews.

This looks very promising but it desperately needs tab hiding for it to be usable (upstream limitation I know).