The Flier alert stays active for 1 hour from the time it was triggered, so changing your setup won’t fix the issue. You just need to wait for it to expire as we have no way to manually remove it.
As for what happened, Zwift never asks you to calibrate your trainer, so I’m guessing you’re seeing one of two things: either the calibration button on the pairing screen (which we actually don’t recommend using until after the September release due to bugs affecting various smart trainers) OR the flier alert message which asks you to check your setup.
If you saw the flier alert message and that’s what prompted you to calibrate, they’re actually unrelated - and I suspect the reason you were flagged was more likely due to a falsely triggered bug that happens when you start an event after riding on the course in the same session. The best way to avoid this issue for the time being is to do any ride you plan on before the event - save and exit - and then log back in and join the event. We know it’s a pain, but it’s the best workaround for now until this bug is fixed.
If there’s any other questions about this, please submit a ticket, and we’ll work with you further there. Sorry for the bugs, and thanks for your understanding. We should have this cleaned up soon.