When you turn on "Make collapsible" in the table of contents, a "Open by default" toggle appears below it (on by default, does not change the behavior of existing blocks). When turned off, it is displayed in a collapsed state and opens when clicked. On the front end, I verified on a real device that it goes from collapsed to clicked to open.
1.6.1
Resolve the error where the table of contents does not appear when placed in a template
