Issue locked during ediit

Hi,
I was using issues in GitLab with a colleague and noticed the following
I opened issue for edit.
Colleague opened same issue for edit
I made changes and saved
He made changes and saved
My changes lost and he never saw my changes

So is there locking in Gitlab? Are we using this incorrectly?

Regards,
John

So can I assume from the lack of replies that gitlab does not have issue locking?

Correct. That currently is not a feature.