This happens to me often, and although I’m not diagnosed schizophrenic, I’ve had difficulties with top-down processing due to brain injury and I think this influenced me to see people I expected to see, wanted to see, or feared seeing in random people’s faces in public. Sometimes they looked nothing like the person I thought they were but I still thought it was them for a second.
That’s weird but maybe you can relax yourself out of it. Get being in a crowd without thinking about it.