I'm on Kubuntu, and I'm experiencing the same behavior. As a workaround, adding the following in the "[Settings]" section of ~/.config/gtk-3.0/settings.ini or /etc/gtk-3.0/settings.ini fixes it for me:
gtk-primary-button-warps-slider = false Why the behavior is incorrect in the first place is a reasonable question to ask. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1576052 Title: Scrollbar on gtk3 has inconsistent behavior To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1576052/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
