2006 Audi A4 2.0T 108k miles

Started about a month and a half ago during the cold and threw a misfire code so my shop changed the plugs and PCV Valve. Since then I have blown that PCV diaphragm and 2 others. The next move is that they want to change the valve cover but that doesn’t make any sense to me?

Has anyone had this issue before?

Would changing a valve cover reduce crank case pressure?

thanks