Shift click not working on my HP pavilion notebook

[That_time_when]

So, I'm using a HP pavilion notebook. And lately the 2 shift buttons haven't been working for me. I even checked for it in http/www.keyboardtester.com/ and it didn't detect any input from them. Sticky keys aren't activated and I'm using the administrator account.

But one strange thing I've noticed, is whenever I hold both shifts at once then I click on z it types zq. If I hold z, it types zqqqqqq.... This doesn't happen when I hold only one shift.

This happens with q as well, it types zq and when I hold it with both shifts it types zqqqqq...

Apparently it also happens with all the keys of qwertyuiop where they are typed along with the respective keys of zxcvbnm,./

As for the middle keys of asdfghjkl;' nothing happens when I hold both shifts and then press them.

 

[robert600]

I'm not sure what version of Windows you are using but ... what happens when you use the virtual (on-screen) keyboard?

 

[That_time_when]

I'm not sure what version of Windows you are using but ... what happens when you use the virtual (on-screen) keyboard?

It works on the on-screen keyboard.

The really weird thing is, the shift key wasn't working yesterday.
I'm 100% sure that nothing hardware-based happened to it.

Today, the shift key is working.

Then, during today, it stopped working sometimes. I held it for some time then it worked again.
Also when I hold both shifts it still does the zqzqzqz thingie

Oh yeah, I'm using Win10