Not that I expect it to be the reason for this, but I note in your code, you’re importing the Velo module, but the documentation you linked to is for the SDK. We tend to encourage the use of the SDK for new code since Velo is deprecated.
That said, this appears like it may be a bug - will raise it with the team, but would encourage you to open a bug report for it to - Wix Studio - How to report a bug