_+1 for the issue repport.
Having similar issue, not sure for how long, but at least several weeks.
OS: Win 10.
When someone gives me a rideon most of the time I do not receive any visual on-screen notification (the small text on top with message that specific user gave a rideon). But in the end of the ride, later, I could see some rideons inside Campanion app.
It might be some new issue that appeared after the latest updated?