Also, does the bug still occur if you close Firefox before locking the screen?
If not then this may be related to bug 1832816. ** Summary changed: - Ubuntu 19.10 (alpha) lockscreen freezes + Locking and unlocking the screen is slow and stuttery ** Tags added: performance -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1832812 Title: Locking and unlocking the screen is slow and stuttery To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1832812/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs