Can’t seem to find much information on this but I can still install Firefox with a PPA.
From the snap install command error: cannot install “firefox”: Post “https://api.snapcraft.io/v2/snaps/refresh”: dial tcp 127.0.0.1:443: connect: connection refused
ufw is inactive - the firewall
from the journal Sep 14 11:31:50 E6540 snapd[10162]: api_snaps.go:366: Installing snap “firefox” revision unset Sep 14 11:32:15 E6540 snapd[10162]: stateengine.go:149: state ensure error: Get “https://api.snapcraft.io/api/v1/snaps/sections”: dial tcp 127.0.0.1:443: connect: connection refused Sep 14 11:41:08 E6540 snapd[10162]: api_snaps.go:366: Installing snap “firefox” revision unset