What's wrong?
I've looked the video and doing all the same things, but by me this don't work!




I'm using krita 4.2.8 portable!

Edit:
After zooming in and then using the moving tool it works.
Bug?!

The only time I see anti-aliasing effects like that is if I have anti-aliasing set in the Tool Options docker.
If anti-alisasing is turned off, I don't get that no matter what the zoom level when I perform the selection and move operation.

Can you repeat the process to get that effect to demonstrate that there is a difference at different zoom levels?

Yes, I can reproduce the problem.
First i closed krita and opened it again.
Now i've let the Anti-aliasing disabled (!) and draw the circle.
(1.)Then i've used outline selection and then the Move Tool to move the selection (no problem).
(2.)To reproduce the problem you have to activate the anti-aliasing by using the outline selection and then the Move Tool to move the selection (no problem too).
(3.)Then disable Anti-aliasing (again) by using the outline selection and then the Move Tool to move the selection -> problem!

I've just tried what you said with the 4.2.8 portable .zip running on Windows 10.
I do not get that at all after repeated attempts.

Are you setting anti-aliasing to be 'off'/ 'on' after you've made the selection outline? If so, that would explain this since the anti-aliasing setting applies while the selection is being made. It cannot be changed after the selection outline has been completed.

If you're setting anti-aliasing to be 'off'/'on' for the selection tool before you make the selection then you do have some kind of bug but it's not one that I can reproduce.

Ahh, ok, i didn't know that.

Everybody experiences something like this at some stage