Zoom in/out not working with shortcuts on numpad

Problem: When using CTRL with + or - key on numpad, the font size of the terminal won't increase/decrease. This shortcut is working 100% everywhere else (Thunar, chrome etc.) but not in the terminal. It's working well when I use - or + button on the top of the keyboard. I use the latest version of Xubuntu 20.04, all updated.