(Note: this is on a LG phone, Android 7.1.2)
Honestly, I haven't thought of just 'tapping'; I did try swiping, but that brings up the options for 'permanent notifications' of [Block All][Silently Notify][Don't Silence or Block].
I connect to WiFi at work; that's another unsecure network. I can also connect at home, and it's considered secure (enough) by Avast. Today I got the 'stuck notification' of Unsecured WiFi even though I was on my phone internet, heading from work to home; I ended up seeing what would happen if I connected to he home WiFi -it still showed the Unsecure warning for the work WiFi SSID. A rescan made the notification disappear. (Previous times were me rebooting the phone.)