Today has been my initiation with the connectivity check. I’ve never seen it before and had no idea what was wrong. In addition to limited connectivity notices, wifi connects fine but with another notice saying “unable to reach the internet” which sent me to the router’s reset button, among other things.
Before this thread was started I found the same post @acarasimon96 mentions and it helped get Manjaro online without the exclamation mark. I’m relieved and glad to have my sanity back regardless of when it’s ok to remove 20-connectivity.conf.