Missing fonts after Signal-desktop installation

Operating System: openSUSE Tumbleweed 20210107 /KDE
snapd latest/stable: 2.48.2
signal-desktop latest/stable: 1.39.4

I installed Signal-destop with snap commands below

sudo zypper addrepo --refresh https://download.opensuse.org/repositories/system:/snappy/openSUSE_Tumbleweed snappysudo zypper --gpg-auto-import-keys refresh
sudo zypper dup --from snappy
sudo zypper install snapd
sudo systemctl enable snapd
sudo systemctl start snapd
sudo systemctl enable snapd.apparmor
sudo systemctl start snapd.apparmor
sudo snap install signal-desktop

When I use “+ command” (see images 1 and 2) only squares appears.
I use fonts Roboto 12pt and Hack 12pt

Well, I could not upload pictures… (I don’t know how to change password to https://paste.opensuse.org/login. Get all the time: Authentication error; not a valid OpenID. These pages are pretty awfully difficult to use. No wonder there aren’t many pictures, even if they say more than 1000 words). >:(

Any way they look like this ]]]]] ]]]

ps. The ten-minute time limit is far too short for me if I try to formulate a good question in the slightest. You must always start over.

That is nonsense. You can take as much time as you want to create a post. As long as you do not post it, you can change what you want until you are satisfied that you have made a consistent story with all the facts you want to provide. Using the Preview will always show how it is presented to others and you will then still be able it to change if you want.

When you really have problems in formulating a post in one go, the my advice is to first create a local document, sleep a night over that, make it better and when you think it is OK then copy/paste it into a post.

URL: https://paste.opensuse.org/91972433
URL: https://paste.opensuse.org/84030143

Ok. Some how I managed to create 3 posts.

But fact is that these pages are not the best, not user friendly.

I have done myt best.

I still wait for answer for question.

Workaround

rm -r ~/snap/signal-desktop/common/.cache/fontconfig 
touch ~/snap/signal-desktop/common/.cache/fontconfig