Can you reproduce the problem with an upstream build of firefox (downloaded from https://download.mozilla.org/?product=firefox-latest-ssl&os=linux64&lang=fr)?
Would you mind filing an upstream bug report at https://bugzilla.mozilla.org/enter_bug.cgi?product=Firefox, and sharing the link to it here?
Can you reproduce the problem with an upstream build of firefox (downloaded from https:/ /download. mozilla. org/?product= firefox- latest- ssl&os= linux64& lang=fr)?
Would you mind filing an upstream bug report at https:/ /bugzilla. mozilla. org/enter_ bug.cgi? product= Firefox, and sharing the link to it here?