The indexes and Table of Content are not automatically updated.
One needs to right-click the index or table and choose "Update Index or Table".
This is error prone, since one may forget to update before, e.g., exporting to pdf.
I propose as an enhancement to automatically update the index or table, at least optionally.
Thanks for posting this. The wish already is noted: bug 44448
Cheers - Cor
*** This bug has been marked as a duplicate of bug 44448 ***