How to turn off Left Alt + A keyboard shortcut? Polish letter conflict.

When I’m typing a word with Polish letter ‘ą’ I’m selecting all text so my text is gone in the middle of typing. Every time I have to type something with that letter I have to stop after this letter, click right arrow to deselect and go back to typing. Letter works fine but at the same time it’s selecting all text. For selecting all text should only work Ctrl+A, not Alt+A.