Windows 10 can't enter Shift + 12347890 without typing the number first

Question

I have been suffering an issue where my computer will refuse to type the symbols !@#$&*() without me typing one of the numbers they're on first.

This is getting in the way of me coding, since to enter parentheses, I need to first type 9, delete that 9, then press Shift+9 for the letter I actually want.

I have uninstalled Keyman, as I thought it may be interfering with normal functionality of the other keyboards. The issue persists.

I am currently using the Dvorak keyboard layout, but the issue also occurs in Japanese with Microsoft IME.