Missing fonts after installing Signal-desktop to openSUSE Tumbleweed

Operating System: openSUSE Tumbleweed 20210107
KDE Plasma Version: 5.20.5
KDE Frameworks Version: 5.77.0
Qt Version: 5.15.2
Kernel Version: 5.10.4-1-default

snapd 2.47.1-3.41
signal-desktop 1.39.4 snapcrafters

I installed Signal-desktop to openSUSE Tumbleweed with commands below

sudo zypper addrepo --refresh https://download.opensuse.org/repositories/system:/snappy/openSUSE_Tumbleweed snappy
sudo 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” down right only squares are outputted to screen ([][][] [][])

localhost:/home/raija/.fonts # snap connections signal-desktop
Interface Plug Slot Notes
audio-playback signal-desktop:audio-playback :audio-playback -
audio-record signal-desktop:audio-record - -
browser-support signal-desktop:browser-support :browser-support -
camera signal-desktop:camera - -
content[gnome-3-28-1804] signal-desktop:gnome-3-28-1804 gnome-3-28-1804:gnome-3-28-1804 -
content[gtk-3-themes] signal-desktop:gtk-3-themes gtk-common-themes:gtk-3-themes -
content[icon-themes] signal-desktop:icon-themes gtk-common-themes:icon-themes -
content[sound-themes] signal-desktop:sound-themes gtk-common-themes:sound-themes -
desktop signal-desktop:desktop :desktop -
desktop-legacy signal-desktop:desktop-legacy :desktop-legacy -
gsettings signal-desktop:gsettings :gsettings -
home signal-desktop:home :home -
network signal-desktop:network :network -
opengl signal-desktop:opengl :opengl -
removable-media signal-desktop:removable-media - -
unity7 signal-desktop:unity7 :unity7 -
wayland signal-desktop:wayland :wayland -
x11 signal-desktop:x11 :x11 -

Should I download some Gnome desktop files, or how could I fix this?

Please refer to the workarounds provided in other threads eg.

Hurrah!

I’ve searched online repair this problem for several days. And now the signal-desktop is working properly.

Thank you, mborzecki