I need to make a hole on the surface of my sun shading,the problem is that I make it like the first image below but when I reopen my OS model the hole is disappeared!(and the sun shading is without the hole like second image below.)

Thanks in advance for any guidance!

I need to make a hole on the surface of my sun shading,the problem is that I make it like the first image below but when I reopen my OS model the hole is disappeared!(and the sun shading is without hole like second image below.)

Thanks in advance for any guidance!

 I need to make a hole on the surface of my sun shading,the problem is that I make like the first image below but when I reopen my OS model the hole is disappeared!(and the sun shading is without hole like second image below.)