Calc Black Background on loading

Hi there,
I’ve recently installed
Version: 7.5.7.1 (X86_64) / LibreOffice Community
Build ID: 47eb0cf7efbacdee9b19ae25d6752381ede23126
CPU threads: 4; OS: Windows 10.0 Build 19045; UI render: Skia/Raster; VCL: win
Locale: sv-SE (en_GB); UI: en-GB
Calc: threaded
and now, whenever I load a file, the entire CALC window has a solid black background until the file is loaded.
If I just activate CALC it remains white and if I load a file from the >FILE>Recent Documents list it also remains white but anything loaded from the Taskbar Jump List or double cliking a file or shortcut produces the black fill.
Any idea if this is a bug, or a new feature of CALC or WIN10 - which was auto-updated at around the same time?
Added: It doesn’t present like that in Excel.
Thanks for any insights

Hi!
I checked by opening an obviously large spreadsheet (so that it would take as long as possible to load). Solid fill of regular light gray color. Perhaps this is because I never play with Themes, neither with Operating System Themes, nor with Office Themes? (I always leave the default values - I am pragmatically interested in functionality, not design)

Thanks JS,
I don’t use themes either, just the auto colour differentiating formula results from “text” input.
Mine starts black and then changes to the “standard” grey part way through the loading process.
It’s definitely a “new experience” though.
I think I’ll try another “identical” PC to see if the results are any different.
Thanks again.

Hi again,
Same effect on an “identical” PC with a freshly installed LO and the same OS.
Were you using Windows and 7.5.7.1?

Version: 7.6.2.1 (X86_64) / LibreOffice Community

I have another box and I think I may already have 7.6 on that so I’ll try again.

Works fine for me on that here as well.
Obviously somebody noticed and fixed it.
Thanks for your time