Very often, the shortcut for making checkboxes does not work for items in the tree branch underneath the line you apply the shortcut too. I don’t know what the problem might be.
I would expect that Ctrl + Shift + C would show or hide checkboxes in the lines underneath (tabbed under) the overarching line. Instead, nothing seems to happen. The checkboxes stay put.
I’m using the dynalist software for Windows 10. The same problem happens in the web version of Dynalist in Chrome.
Below a screenshot of the situation.