They sent me an email letting me know "it's time to check in online."

B@stards.

@Cheri I made the mistake of googling possible reasons this happens. It's almost like googling health issues; I've immediately gone to the worst-possible outcomes. "Your flight's cancelled but they're not going to tell you until you get to the gate," etc. 😅

@richText In our case they needed to check our ID or vaccination cards. A bit inconvenient but no big deal. Hopefully yours is NBD too.