I figured out what is causing the issue. My reasoning was based on the input of this thread, so thanks a lot everyone!!!
Try to add an “opt-in to Cookies” action, after you do once it should work without any issues.
Can you give it a try and let me know if it works for you?

Edit 1
If some data are not available in the workflow or they disappear (like for me) check the privacy rules, they did not have any effect a week ago since no user is logged in but it is not the case anymore.
In my case I could access via workflow to the user data but some of these were not working (available on debug but not working on run). I changed the privacy rule and now the whole workflow runs.