deployment_token invalid when deploying from Gitlab

**Describe the bug**

When deploying from Gitlab the following error shows up:
deployment_token provided was invalid.
An unknown exception has occurred

My app deploys just fine on Github, but company wants to move it to Gitlab. In order to achieve this I have followed the steps in: https://learn.microsoft.com/en-us/azure/static-web-apps/gitlab?tabs=vanilla-javascript
Tried with the demo vanilla-javascript app, tried with my own github repo, tried manually executing entrypoint with hardcoded variables, even set up a new gitlab account and a new azure subscription, to no avail.