Hi,
Here is a file I composed to that reproduces the issue at least on my setup. You can download it from WeTransfer: https://we.tl/t-AVFFog8NUQ
This time, all the images are affected.


Thanks for file. I reproduce your glitch as I don't think this is a bug. I think its a way that xd works.
It happens when your mask is not Mask Group.
Variant 1
Place an bitmap and then draw on a shape on bitmap then Make Mask. Xd will create a Mask Group in Layers After copy/past into Ai it will not create a pattern as Ai import to different objects
Variant 2
If you drop an image into shape and then copy/past into Ai it will create a pattern (and the pattern is flipped).
But the Mask Grope from your file also create the pattern, Please try Variant 1 in new file and see if the pattern will be created again?.
Thanks
