Thank you for your bug report, can you take a screenshot showing the fullscreen status? Also what screen resolution are you using? The calendar default being the text editor mentioned in the title is known as bug #876689
** Changed in: gnome-control-center (Ubuntu) Importance: Undecided => Low ** Changed in: gnome-control-center (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-control-center in Ubuntu. https://bugs.launchpad.net/bugs/1855569 Title: The application does not open on the main monitor, but on the secondary one. Also, the text editor is incorrectly specified as the default application for the calendar and cannot be changed. Status in gnome-control-center package in Ubuntu: Incomplete Bug description: When you start the program runs on the second monitor, which is connected via HDMI. This is repeated all the time. Also, the application always opens in full screen. ProblemType: Bug DistroRelease: Ubuntu 19.10 Package: gnome-control-center 1:3.34.1-1ubuntu2 ProcVersionSignature: Ubuntu 5.3.0-24.26-generic 5.3.10 Uname: Linux 5.3.0-24-generic x86_64 ApportVersion: 2.20.11-0ubuntu8.2 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Sun Dec 8 14:48:07 2019 ExecutablePath: /usr/bin/gnome-control-center InstallationDate: Installed on 2019-12-06 (2 days ago) InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017) ProcEnviron: LANG=ru_RU.UTF-8 PATH=(custom, no user) SHELL=/bin/bash XDG_RUNTIME_DIR=<set> SourcePackage: gnome-control-center UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1855569/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp