Description of problem:

The right-click menu sometimes doesn't appear when I've right-clicked in konsole in Plasma 5.15.5 on Wayland with Qt 5.12.4. The message "konsole[2225]: qt.qpa.wayland: Non-toplevel surfaces can't request window states" happens when the right-click showed no menu. The journal contains messages such as the following when right-clicking in konsole and the right-click menu didn't appear.

Jul 22 19:57:58 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 19:57:58 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 19:57:58 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 19:57:59 plasmashell[1532]: qt.qpa.wayland: Non-toplevel surfaces can't request window states
Jul 22 19:57:59 plasmashell[1532]: QObject::startTimer: Timers cannot be started from another thread
Jul 22 19:57:59 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 19:57:59 plasmashell[1532]: qt.qpa.wayland: Non-toplevel surfaces can't request window states
Jul 22 19:58:00 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 19:58:00 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 19:58:07 plasmashell[1532]: kf5idletime_kwayland: This plugin does not support polling idle time
Jul 22 19:58:37 plasmashell[1532]: kf5idletime_kwayland: This plugin does not support polling idle time
Jul 22 19:58:38 konsole[2225]: qt.qpa.wayland: Non-toplevel surfaces can't request window states
Jul 22 19:58:39 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 19:58:44 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 19:59:07 plasmashell[1532]: kf5idletime_kwayland: This plugin does not support polling idle time
Jul 22 19:59:37 konsole[2225]: qt.qpa.wayland: Non-toplevel surfaces can't request window states
Jul 22 19:59:37 plasmashell[1532]: kf5idletime_kwayland: This plugin does not support polling idle time
Jul 22 19:59:40 konsole[2225]: qt.qpa.wayland: Non-toplevel surfaces can't request window states

The File, Edit and other menus in konsole have also showed nothing when I've clicked on them sometimes in Wayland. The same type of errors were in the journal when the File, Edit menus in konsole didn't appear.

Jul 22 20:52:58 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 20:53:07 plasmashell[1532]: kf5idletime_kwayland: This plugin does not support polling idle time
Jul 22 20:53:10 konsole[2225]: qt.qpa.wayland: Non-toplevel surfaces can't request window states
Jul 22 20:53:11 konsole[2225]: qt.qpa.wayland: Non-toplevel surfaces can't request window states
Jul 22 20:53:12 konsole[2225]: qt.qpa.wayland: Non-toplevel surfaces can't request window states


I've seen the same behaviour in okular and kate. Clicking on the File menu in kate which didn't appear was associated with the following journal messages.

Jul 22 21:08:01 plasmashell[1532]: qt.qpa.wayland: Non-toplevel surfaces can't request window states
Jul 22 21:08:04 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 21:08:05 kate[3485]: qt.qpa.wayland: Non-toplevel surfaces can't request window states
Jul 22 21:08:07 plasmashell[1532]: kf5idletime_kwayland: This plugin does not support polling idle time
Jul 22 21:08:09 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 21:08:09 plasmashell[1532]: qt.qpa.wayland: Non-toplevel surfaces can't request window states
Jul 22 21:08:09 plasmashell[1532]: QObject::startTimer: Timers cannot be started from another thread
Jul 22 21:08:10 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 21:08:11 plasmashell[1532]: qt.qpa.wayland: Non-toplevel surfaces can't request window states
Jul 22 21:08:11 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 21:08:37 plasmashell[1532]: kf5idletime_kwayland: This plugin does not support polling idle time
Jul 22 21:08:39 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 21:08:39 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 21:08:40 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 21:08:40 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 21:08:42 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 21:08:43 plasmashell[1532]: qt.qpa.wayland: Non-toplevel surfaces can't request window states
Jul 22 21:08:43 plasmashell[1532]: QObject::startTimer: Timers cannot be started from another thread
Jul 22 21:08:44 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 21:08:44 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 21:08:44 plasmashell[1532]: qt.qpa.wayland.backingstore: Delivering update request through fallback timer, may not be in sync with display
Jul 22 21:08:44 plasmashell[1532]: qt.qpa.wayland: Non-toplevel surfaces can't request window states



Right-clicking on the Plasma desktop on Wayland also doesn't show the right-click menu sometimes.

Version-Release number of selected component (if applicable):
kate-0:19.04.2-1.fc30.x86_64
kf5-kwayland-0:5.59.0-2.fc30.x86_64
konsole5-0:19.04.2-1.fc30.x86_64
okular-0:18.12.2-1.fc30.x86_64
plasma-desktop-0:5.15.5-1.fc30.x86_64
qt5-qtbase-0:5.12.4-3.fc30.x86_64
qt5-qtwayland-0:5.12.4-4.fc30.x86_64


How reproducible:
The menus not showing up has happened about 30-50% of the times I've tried to right-click or select File, Edit menus in konsole, okular, and kate.

Steps to Reproduce:
1. Boot F30 KDE spin fully updated with updates-testing enabled
2. log in to Plasma on Wayland from sddm
3. start konsole
4. right click in the main part of the konsole windows many times
5. select the File, Edit, menus in konsole many times
6. journalctl -b

Actual results:
The right-click and File, Edit menus in konsole sometimes haven't appeared on Wayland

Expected results:
The menus appeared normally.

Additional info:

https://bugs.kde.org/show_bug.cgi?id=409104 involved the `
qt.qpa.wayland: Non-toplevel surfaces can't request window states
message with spectacle. The patch for qtwayland at https://codereview.qt-project.org/c/qt/qtwayland/+/265999 might address this problem according to https://bugs.kde.org/show_bug.cgi?id=409104#c5

I haven't seen this problem in Plasma on X. This problem seemed to start with Qt 5.12.4. The issue seems more common after the qt5-qtbase-5.12.4-3
qt5-qtwayland-5.12.4-4 update https://bodhi.fedoraproject.org/updates/FEDORA-2019-6a476fd9b1