Vivek, This is a 4 year old bug reported by someone else on a different Ubuntu version with likely different hardware. Please open your own bug by running:
ubuntu-bug gnome-shell -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1769981 Title: Temporary screen freeze when coming back from screen standby To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1769981/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs