Stop using gitlab.com for projects - Credit card info required for new registrations
If your IP (and possible your browser) looks "suspicious" or has been used by other users before, you need to add additional information for registration on gitlab.com, which includes your mobile phone number and possibly credit card information.
Since it is not possible to contribute or even report issues on open source projects without doing so, I do not think any open source project should use this service until they change that.
I created a GitLab account long before they implemented this, but never used it. Went to post an issue related to self-hosted GitLab on their issue tracker, and it told me my account was banned. I wrote an email to support and they essentially said "an automated system identified your account as a bot and banned you during an account clean up some years ago to cut back on malicious users". I informed them that this was not at all reasonable, as I've never even posted anything on any GitLab account, and that I would be advising my organization to never pay for any GitLab product or service unless legal writes up the contract terms, because I have no faith in them as a vendor.
Seriously, fuck GitLab. And if anyone from that org wants to discuss this with me, they can pipe their email to /dev/null
That is regrettably not too unusual. Many platforms deactivate / ban empty accounts that were inactive for a long time. I guess "aging" accounts before use is something not too uncommon for bots.