Hi there. If you use user id, the visitor id is derived from it. Could you explain what exactly you’d like to achieve? I mean, what would be the scenario you want to cover - e.g. switching from being anonymous to have a user identified without creating an additional session?
Ok, so it should work. For now it’s hard to debug it, because the first event with user_id overrides the visitor ID. But if it appears the first time, it should convert the anonymous session into one having user_id set. You can check it by sending two tracking requests:
One with min no. of params like idsite, rec=1, page title, url and id. It would be nice to have a fresh visit only with this one event. You can force that by using for instance a different browser.
Another one with same params, but also user_id set.
You should end up with one session having both those page view events.
Next week I should have bit more time so I’ll make sure that we have all the scenarios documented.