When transferring groups to another account, Roblox Automated Security will flag the new ownership. This can result in the new owner being removed from the group, and the ownership not being transferred correctly. Instead of returning ownership to the old owner, this issue allows others to claim ownership of the group.
This problem has affected many of my friends. When contacting support, they only restore the group to the old owner, not the intended new owner.
To everyone reading this, avoid transferring groups at this time until this issue is fixed.
A private message is associated with this bug report