in reply to Strange qx under windows behaviour

But from some reason, a couples of days ago it stopped working!

... and "stopped working" means... what, exactly? What evidence do you have about its failure to work? Usually, there is some sort of error message, and even when there isn't, there is some specific expectation that is not met, for example: files that should no longer exist are still there, or files that should not have been deleted are gone. (Which was it in your case?)

It's hard to explain something when no evidence is provided.