1.9.5 : Grey-8 / Zoom goes blank

[meteorquake]

If you perform Image - Change colour depth - Greyscale 8
It looks okay but when you zoom in (eg ctrl mousewheel into the centre) after a bit of zooming in it suddenly goes blank
1.9.5 64b Win11
Example image. Let me know if you find differently, I glanced but didn't spot it reported.
d

[xnview]

what do you have in Settings>View - Anti aliasing?

[meteorquake]

I have Out Bilinear, In Spline 36

d

[xnview]

Thanks to your detailed description I can reproduce the problem.