Unable to log in twice without clearing cache

Hello and thanks for this plugin.

I’m using it to let users log in with a “guest” account. It works well, whereas a user can click my “Guest” link, and be immediately logged in with my “guest account.”

My issue comes when the “guest” logs out, then tries to log back in; the link doesn’t log “guest” in the second time around, unless the user clears cache in their browser.

I understand that the plugin wasn’t intended for this purpose, but by any chance, could you offer any suggestions?

Thanks!