I experienced the exact same problem (and resolution) as @markmacallister. Changing to a WordPress default theme did not have an effect (the problem still existed). No other plugins caused a problem (they were all deactivated and reactivated to isolate the source of the problem). I could not find any discussion in the WordPress forums of this problem occurring globally with the update to WordPress 6.1.
It’s a handy plugin, so it would be great if you’re able to fix it.
Thanks!