Recently I came across the same issue. I was able to ssh to my pi on my network, but not from outside my home network. I had already: installed ...
could-not-resolve-the-hostname
939c2ea5af
ssh could not resolve hostname, git ssh could not resolve hostname, scp could not resolve hostname, ssh could not resolve hostname github.com, git could not resolve hostname, ssh could not resolve hostname gitlab, could not resolve hostname raspberrypi.local, can't resolve hostname minecraft, can't resolve hostname, can't resolve hostname aternos, can't resolve hostname windows 10, can't resolve hostname hypixel, can't resolve hostname linux, can't resolve hostname on local network, can't resolve hostname over vpn, can't resolve hostname ubuntu, can't resolve hostname mac