[Ubuntu] IDE not displaying spaces, tabs and digits

[git-yoyo]

Installed Arduino IDE version 1.8.10 64bit on Ubuntu 19.10. The software seems to be working fine but digits, spaces and tabs do not display when writing/pasting/opening code in the editor, which makes it completely unusable.
(I can delete tabs/spaces/digits and they display correctly when copy-pasting to a text file, so it's probably just a display problem).
Same issue with the console below as you can see in this screenshot:

[facchinm]

Hi @git-yoyo ,
which is the default locale in your machine? Did you install any non standard font? Thanks for reporting!

[git-yoyo]

Hi @facchinm ,

System language is set to English (United States) and input to French, here is the full /etc/default/locale file:

LANG="en_US.UTF-8"
LC_NUMERIC="fr_FR.UTF-8"
LC_TIME="fr_FR.UTF-8"
LC_MONETARY="fr_FR.UTF-8"
LC_PAPER="fr_FR.UTF-8"
LC_NAME="fr_FR.UTF-8"
LC_ADDRESS="fr_FR.UTF-8"
LC_TELEPHONE="fr_FR.UTF-8"
LC_MEASUREMENT="fr_FR.UTF-8"
LC_IDENTIFICATION="fr_FR.UTF-8"

I did not install any font on my system, though I ran
sudo apt install libcanberra-gtk-module libcanberra-gtk3-module after noticing a Failed to load module "canberra-gtk-module" error when running arduino from the terminal. It fixed the error but not the display issue, so I don't think it had anything to do with my problem.

[ubdussamad]

Hi @git-yoyo , is this issue just localized to the editor or is it happening in the UART ( Serial monitor ) window as well?

[bparker667]

I am having the same issue... has anyone figured out how to fix this yet?