I'm trying to get a virtualbox [Version 6.1.4r136177 (Qt5.6.2)] install of CorePlus 11.x (downloaded Mar 5, 2020) working as a development platform to (re)build some of our linux programs so they will work with Core. Everything appears to work great EXCEPT for the mouse on the graphic desktop...
There seems to be a somewhat random rectangle where the mouse works. When the mouse reaches the (invisible) edge of this rectangle, the mouse pointer suddenly jumps outside the VirtualBox window entirely, back to Windows (freezing the VM's mouse pointer somewhere within the VM window.) Strangely, the "mouse rectangle" seems to move around within the VirtualBox window during the session, too. Unfortunately, this renders the graphical desktop unusable.
(I'm going to work around my problems by using DropBear to allow me to access the VM from Windows with PuTTY, but I would prefer to work directly within the VM.)
I found this article
http://forum.tinycorelinux.net/index.php/topic,15659.msg91561.html#msg91561 that mentions what I think might be the same mouse issue from several years ago, but I cannot find any way to disable mouse integration in the current VirtualBox, so it no longer seems to apply.
[EDIT] If it helps, the TinyCore boot shows Core 11.0 5.4.3-tinycore