Bartender 3

If the gear icon looks like this:

Then this is Script Monitor, part of macOS that is displayed when a script is running, to be able to set settings for this in Bartender you can download the this automator script that is just a 60 second pause, running this will display the gear icon long enough for you to be able to see it in Bartender preferences, and set you desired settings for it. If you cant see it you can refresh the menu items in Bartender preferences with the refresh button at the bottom of the left hand list, you are looking for Script Monitor.