@team replacing gitlab will be a large task. You'll have to do all the work of setting up replacements for every aspect you use. Gitlab had project planning, source control, CI, all rolled into one thing. It would be a lot easier just to get the source control to work.

Actually, now that I think about it I have to ask, why don't you directly use Gitlab's source control capabilities? You're already paying for them. You could drop gitea and just use Gitlab.