

Happy to gather other debug if it will be helpful! Since upgrading to Debian 9, seamless mode has become unusable, and the toolbar is in the wrong place in full screen mode. Previously, I was using Debian 8 (Jessie), and was able to run in seamless mode across all 3 monitors without major problems (On VirtualBox versions through to 5.1.22). It seems if I switch the guest to be fullscreen on monitor 3, the toolbar then appears in the correct place. The VirtualBox guest is full screen on monitor 1 (right hand screen), but the toolbar is appearing on monitor 3 (left hand screen) It seems VirtualBox tries to number them differently (and was previously), the numbering it uses is:

With the primary (Linux menus) on screen 2. My monitor setup, as shown in the display configuration is: In full screen mode, I initially thought the mini toolbar did not appear at all, but now have found it is appearing on the wrong monitor. Whether you have multi-monitor host and guest configuration or not Also, please no need to add things like "happens for me as well", that makes it difficult to understand what exactly issue and which exactly VBox version you are referring to. Whether you have multi-monitor host and guest configuration or not.Effective Qt5 version used (written in VBox About dialog),.So I wanted to ask you to do the following thing: everyone who wants to speedup the fix progress of that exactly annoying issue please check VBox of any version *newer or equal to 5.1.20* (just using the latest one would be enough) and write down a report here in the form: This rework had fixed some of the issues you might referring but certainly not every of them (there could be even regressions we are not aware of). Latest rework regarding the mini-toolbar behavior under X11 was released in 5.1.20.

We are not aware of any issues under Windows or macOS hosts, so if there are any, please let us know. Nowadays mostly all of them are about *very* arbitrary (unstable) Qt5 behavior under various X11 desktop environments (DE) and window managers (WM). We are aware of some of the issues related to the mini-toolbar functionality. First of all I wanted to thank you for your reports.
