Sounds like a mobile-vs-desktop issue, since the error mentions TouchEvent. The Firefox error fires even when just hovering the cursor over the PDF in View mode, and text is also not selectable.
While I'm here, a suggestion to add Undo/Redo; yes HN, I know I could make a PR..
Thanks for pointing that out! I’ve fixed the Firefox issue. And we actually already have Undo/Redo on the annotation toolbar.