I use for example the repo https://bitbucket.org/CloneVince/trackr (protected).
With 184.108.40.206 I can move a tag without any problem.
Since 1.8.x version, when I try to move a tag, I have the question "Tag Already Exists!...", I choose the button "move tag", and then I have this message : "hint: Updates were rejected because the tag already exists in the remote."
I've rollbacked on 220.127.116.11 version and it's OK again with the same repo.
Thx for your help to remove this bug.