Convert VECTOR pattern to editable vector objects?

Not inside the program, but if you export to a vector format (like EPS) and import it back in again, you will get vector objects.

My goal is to change the Black-White hatch  into a Black-Grey hatch

I have Corel Draw X8 and Illustrator C4.

Your approach does unfortunately not work for me, and I don't get why not.

I create a shape, and fill this with the desired vector pattern. When I export this as .eps or .ai and then import into Corel Draw (your approach) or open with Illustrator (as suggested here: https://graphicdesign.stackexchange.com/questions/64147/change-vector-fill-colors-in-corel) , respectively, the pattern is completely lost. There are no objects at all.

I cannot follow the suggestion by Mosh (https://community.coreldraw.com/talk/coreldraw_x3_and_older/f/coreldraw-x3/14673/can-you-change-colors-on-a-vector-pattern), there is no Patterns folder in my installation path and there are no .pat files whatsoever.

I cannot use the 2 color pattern because there is no comparable hatch pattern in these. (suggestion by Ariel https://community.coreldraw.com/talk/coreldraw_x3_and_older/f/coreldraw-x3/14673/can-you-change-colors-on-a-vector-pattern)

I cannot go via Edit --> Find and Replace --> Replace Objects --> Replace Color --> Replace colors used as fills (as suggested here http://support.epiloglaser.com/article/8205/29944/find-and-replace-a-color-in-coreldraw) . This is because corel draw cannot find any objects.

I don't get, how this seemingly easy gaol can be so difficult to achieve.

Any help would be highly appreciated!

Are there any new insights into this issue? Is the a new and easy solution to that?