localhost web apps and cookie blocking

[Celejar <celejar@gmail.com>]

Hi,

I have various web (HTTP, not HTTPS) apps (e.g., pi-hole, Home
Assistant) running on localhost (either actually on localhost, or on
another host but accessed via 'localhost' via ssh port forwarding
(LocalForward) that require cookies to function (even before logging
in). When Firefox is set to block all cookies, these don't work - even
though I have an exception set to allow cookies from localhost. The
only way I can access these apps is via relaxing Firefox's Enhanced
Tracking Protection to allow (at least) first party cookies in general.
Why? (Examining the cookie store ("Manage Cookies and Site Data")
doesn't show any cookies stored from any site other than localhost.)

This doesn't seem to be an issue for normal web sites, where
whitelisting the website is (generally?) sufficient to get the sites to
work. What am I missing?

Celejar