The new ticket seems to be Lubuntu-specific so I have created a new one for Firefox (as Firefox 55.0.2 on Ubuntu 17.10 dev is affected too): https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1718336
The new ticket seems to be Lubuntu-specific so I have created a new one for Firefox (as Firefox 55.0.2 on Ubuntu 17.10 dev is affected too): https:/ /bugs.launchpad .net/ubuntu/ +source/ firefox/ +bug/1718336