The 1, 2, 3, 4, and 5 keys don’t work when naming something inside of the plugin. But the Numpad keys do work. (Ableton Live 10)
Maybe those keys are dedicated to shortcuts in Ableton. Some plugins can “override” the key-shortcuts when doing text entry. Should be fixable.
Had this exact same problem with Plugins in Ableton Live on Windows, the solution for me was to run Ableton as administrator, this will have to be done every time opening Live.