This has happened 3 times to me, twice on desktop (chrome) and once on android (also chrome). The first time I click the collaborative invite link to a private project, the browser actually opens the hello-world project. If I close the browser and click the link again with no other action, then the correct project opens.
Tried to search these forums, either didn’t find the right terms or it hasn’t been reported? I have confirmed this happens with at least one other user, also on chrome. Also if you paste the link in another browser such as Firefox, same behaviour.