404 when viewing tag created on tree

Hi, i have created a tag on a tree using:

git ls-tree HEAD
100644 blob 8382dc45af209e8f6a928d1b1833cdc861055e21 README.md
040000 tree b6d6ab9bd0701873a393af88edd040761c8698a3 project1

git tag V2 b6d6ab9bd0701873a393af88edd040761c8698a3

We are self hosting the GitLab instance.
When i tried to view the tag within gitlab GUI it shows a 404 error, any suggestions?