I can only press up to 6 keys at once, but there is exception and i dont know why this happens

I have upload similar to this post, but i found something strange

after I got my new keyboard, I found that the keyboard can`t press(or input) 7 or more keys at once, I can only input 6 keys at once, even the keyboard support infinite multi input(every key can be input at once)

but some keys, like Ctrl, Alt, Shift, can input with 6 other keys.
for example, normally I can type 6 keys, like “asdfgh”, “123478”, “asdf” + two arrow keys, but not “asdfght” or something that require to input 7 or more keys at once
but with special keys, I can input more than 6 keys at once, like LShift + “asdfjk”. (7 keys at once)

A post was merged into an existing topic: Pressing multiple keys(more than 6) at the same time doesn’t work