I'm also seeing this on a fresh Ubuntu 20.04 LTS install. Emacs (GUI) started from the Gnome launcher will open a small window without the splash screen graphics. But if I start emacs from the CLI, it will open just fine.
Just once when I opened emacs using the CLI it came up in a small window and I saw the following message m330625@desk7802:~$ emacs (emacs:274762): Gtk-CRITICAL **: 09:48:38.062: gtk_distribute_natural_allocation: assertion 'extra_space >= 0' failed (emacs:274762): Gtk-CRITICAL **: 09:48:38.413: gtk_distribute_natural_allocation: assertion 'extra_space >= 0' failed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2011244 Title: emacs launching in GNOME is all messed up To manage notifications about this bug go to: https://bugs.launchpad.net/emacs/+bug/2011244/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs