Shutdown the computer, wait 30 seconds, restart the computer.The AP itself is fine (I'm connected wtih several devices including a 10.14 Mac, the issue is something to do with ObjectiveDevelopment Little Snitch and Catalina. The Apple Wifi diagnostics is not much help. I have tried connecting to my phone hotspot to remove the router wifi from being an issue. The all-new Silent Mode was re-built from the ground up to make dealing with them a breeze. If you are new to Little Snitch, you may get overwhelmed by the vast amount of notifications from applications wanting to connect to the Internet. I recently installed Little Snitch on my MBP, but all it's been doing is getting on my nerves with the pop-up windows asking me to allow every freakin connection! I deleted the application the traditionl 'drag-an-drop into the Trash' but the windows still keep popping up.

To quite Little Snitch Configuration, you need to right click on its icon on the Dock, choose the Quit option, and click on the Quit button in the pop-up dialog. Before uninstalling any app on OS X, you should quite all related running process(es). Basic Steps to Uninstall Little Snitch Configuration on Mac.

Little snitch for mac 10.12.6 sierra