to add to the already existing issues, it seems to me like there is no way to reopen the TOC once you close it by pressing the X. I believe that this is a pretty important feature that needs to be present. Another Issue is that if you put math into titles, they do not get rendered in the TOC, and the Plain LaTeX is shown
(Feature request) Collapsable Table of Contents #4564
The note table of contents would be nice if the ability to turn off auto-numbering could be added. #3321
(Feature request) - Shared Notes Pages & Table of Contents #3783
to add to the already existing issues, it seems to me like there is no way to reopen the TOC once you close it by pressing the X. I believe that this is a pretty important feature that needs to be present. Another Issue is that if you put math into titles, they do not get rendered in the TOC, and the Plain LaTeX is shown