Yes I think you maybe correct unfortunately.
I had to delete the trigger and recreate it and save the rule again. I was able to edit the rule again only after a power reset / reboot of the hub though.
I have not tried deleting the entire rule and recreating it however, I might try that next, as the trigger doesn’t seem to be working when I want it to.
I want the Site Sensor plugin / rule to notify me when my Site has gone DOWN.
But currently it only runs the rules action when the site is back UP again.
I have tried using both true and false in the rules trigger and both seem to behave the same way and only run the rules action when the site is back UP.
I wrote about that issue here.