I think there's an issue with some recent graphics-related update somewhere between linux mesa drivers, which causes Electron-based apps to fail to render any text.
Microsoft VSCode exhibits this issue too, which is discussed here: microsoft/vscode#190437
Electron seems to have fixed this or worked around it by 26.2.1, so this pushes an update with that new version of Electron.
Correction: upgrading Electron may have caused the GPUCache folder's contents to be [correctly] invalidated, as a side effect, which is a workaround many people have been using for Electron-based apps.
The source issue has to do with Chromium, which is the codebase Electron works off of. Their source bug is being tracked here: https://bugs.chromium.org/p/chromium/issues/detail?id=1442633
This text-rendering issue may be worked around by simply running rm -r ~/.config/ElectroComm/GPUCache (Linux) or similar on other systems.