[philja]

I thought I'd check Windows' sleep function. I set the PC to sleep after 25 minutes and then came back to find Sigil still had its menubar. Doesn't look like a Windows' sleep problem.

I then went to do 20 minutes or so on the linux box (using KVM) - came back to find no menubar.

I used Kevin's #2: maximise the Sigil window (for the record, it was already maximised - I just hit the Windows maximise icon) - and back came the menubar.

I re-instated QtWebEngine GPU acceleration, disabled the Sleep function, and left Windows 10 active while I took the dogs for a walk for an hour. When I returned, Sigil was complete with its menubar.

I switched to the linux machine to do some work and re-checked Sigil in W10 after 15 minutes. The menubar had disappeared. A simple grab of the window and moving it a bit was enough to get the redraw complete with the menubar.

I have been unable to get the menubar to disappear when keeping the Windows box active so maybe I was mistaken on that aspect yesterday.

It does appear that disconnecting the display output from the screen when switching from Windows to linux and then reconnecting by switching back to Windows is the only factor responsible for this mishap. Time is also an element because a simple switch back and forth over a minute or two is not sufficient to cause the menubar to disappear.

Strange though that Sigil GUI seems perfect apart from the missing menubar.