Count IFNULL Function [Help please]

Hi everyone!

I think my formula for the count null if function is wrong.

My expected result:

However, I got,

Wondering if someone can take a look and help me with this. I already tried my best and got no luck

Link for the file: I tried to upload here, it says file not supported. So, I have to upload to external source.

https://easyupload.io/iklv3n