I use two levels of ToC (Main and sub headings). On right-facing pages in a spread, the main heading (TOC-1) appears below the sub-headings (TOC-2) in the Table Of Contents.

Consider the two attached files. The page shown in Toc problem-1 is a right-facing page in the book. The Level 1 heading is "Audible Signals," and the three Level 2 subheads are "Train Whistle/Horn Signals, Train Buzzer Signals, and Tower Whistle/Horn signals. This SHOULD appear with Audible Signals as the top-level and the other three below it. On a LEFT FACING page it works correctly. On a right-facing page it does not. The second file, Bad TOC.jpg, shows what happens on a right-facing page. Two of the subheads get grouped with the previous section.

The fix for this needs to be a Level-1 heading, on a right-facing page of a two-page spread, must always take precedence over Level 2 leadings.