Language switcher flickers and breaks pages on old.webmaker.org

[xmatthewx]

STR:

1. Visit a page:
   • https://old.webmaker.org/en-US/madewithcode-firstwebpage
   • https://old.webmaker.org/en-US/private-eye
   • https://old.webmaker.org/en-US/about
2. Change the language
3. Visit another page
4. URL flickers. Page content does not load

[mmmavis]

This is happening on https://old.webmaker.org/tools and https://old.webmaker.org/getinvolved as well (which blocks mozilla/webmaker-browser#183)