Autostart with Windows: occasionally a blank white window

[ownedbycats]

I have Calibre set to autostart with Windows (it minimizes to the system tray). Once in a while when I open Calibre after a reboot it just fails to render anything and shows a blank white window. Only option is to restart it (forcibly when the system tray right-click fails to render). It doesn't happen every time, only happens with the autostart, and always is fixed when restarting it.

Has anybody else had this issue?

I wonder if it might be a case of somehow the Qt not loading correctly on autostart, but it's a bit difficult to get a debug log under the circumstances.