Custom css themes broken in 4.10.1

[thespad]

Acknowledgements

• I have checked that there is no other issue describing the same or
  similar problem that I currently have, regardless if it has been
  closed or open.

• This bug affects Discord website.

• This issue is confirmed to be reproducible when WebCord is packaged
  on at least all three latest supported Electron major releases.

• This issue is reproducible in Chrome, Chromium or any
  Chromium-based browser, e.g Brave or Edge (please write in
  Additional Context which browser you have used if it is neither
  Chrome nor unmodified Chromium).

• There are no fixes done to master which resolves this issue.

• My issue describes one of the unstable and/or not fully implemented
  features.

• I have found a workaround to mitigate or temporarily fix this issue
  in affected releases (please write it in Additional context section
  below).

Operating System / Platform

🐧️ Linux

Operating system architecture

x64 (64-bit Intel/AMD)

Electron version

32.0.1

Application version

4.10.1

Bug description

4.10.1 seems to ignore existing and new custom css themes (set via --add-css-theme), rolling back to 4.10.0 causes them to start working again.

Additional context

No response