Ctrl, Shift, Alt, and Fn keys suddenly not working anymore

[Ryan360]

My Ctrl, Shift, Alt and Fn keys suddenly stopped working and I have no idea how this happened. I have a HP Probook 450 G2 running Windows 10. Here's a list of the things that I tried to solve the problem;

- Windows Update

- Windows keyboard troubleshooter

- Checking sticky key settings

- Booting in safe mode

- Updating keyboard driver

- Deleting keyboard driver

- sfc/scannow

- Malwarebytes scan

- BIOS update

- BIOS default settings

- Tapping the keys many many times to see if somehow these keys were suddenly stuck

- Creating a second Windows user account

- Intel chipset installation through support.hp.com

- HP PC Hardware Diagnostics Windows tool

From what I can find on the internet, it seems this problem has specifically occurred with other HP users. The HP forums have multiple threads like this, but almost no other notebook brands are mentioned anywhere with this problem. This makes me feel like the problem is HP-related. Can anyone help?

[Ryan360]

I just plugged in the cheap USB-keyboard I ordered yesterday and everything to seems to be working fine on this device.

I'm still hesitant about ordering a new pricy notebook keyboard, since I'm not entirely convinced it's a hardware problem. There are many other posts from HP users encountering the same problem, so it might still be an HP software error. Does anyone have suggestions on how to proceed or is HP willing to send a notebook keyboard to rule out software issues?