Great addon but recent update has overlapping shortcut with default macOS shortcut. shift+option+ left/right arrow key previously could be used to highlight words of text at a time. Recent update has broken this functionality and a way of disabling these shortcuts should be available.

EDIT: Developer is aware of the issue and a fix is on the way. Additional developer has provided a workaround - https://github.com/piroor/treestyletab/issues/3575