Page not found when there are clean extra parameters in URL alias-
I have discovered the problem and the solution. When you change domain, or you add a domain to the list in Domain Access, you later have to switch off SubPath, save, and later turn on SubPath again. In that way, it refresh "something", and everything works perfectly.

So if you have free parameters passed on the clean friendly URLs, you need to make those steps in order to assure that the site will work with the changed or added domains.