Dashboard hangs while trying to connect to fonts.googleapis.com

[j-boy]

When installed in an environment without access to the Internet, the dashboard is slow to open (takes about 30s) and a message at the bottom of the browser window says "Connecting to fonts.googleapis.com..."

To Reproduce
Install in an environment without Internet access.
Open the dashboard page, then open a dashboard from the finder.

Expected behavior
The dashboards should open straight away.

Environment:

$ sudo docker exec graphite cat /etc/os-release
NAME="Alpine Linux"
ID=alpine
VERSION_ID=3.15.9
PRETTY_NAME="Alpine Linux v3.15"
HOME_URL="https://alpinelinux.org/"
BUG_REPORT_URL="https://bugs.alpinelinux.org/"

Additional context
The Graphite docs say that this is a dependency: fontconfig and at least one font package (a system package usually)
I see no fonts installed:

$ sudo docker exec graphite fc-list
$

This page suggests that these font packages are good for most setups:
# apk add font-terminus font-inconsolata font-dejavu font-noto font-noto-cjk font-awesome font-noto-extra

[amai2012]

Did you try building a container with those packages to confirm the fix?

[j-boy]

I had a go at building a container, but it didn't work :(
I mounted a volume for /usr/share/fonts and now can set fonts on the dashboard, but the googleapis timeout is still there.
The dashboard loads the ACE editor, and it is that which is calling out to fonts.googleapis.com.
So the problem is on the client side not the server side. The desktop which is running the web browser also has no Internet access.
Interestingly, the problem doesn't seem to occur when using the Chrome browser, but does appear when using Firefox (both on Windows).