I set the same flow to 3 textframes. In the first frame I have the chapter name, the second frame I have the subchapter name and the third frame the content frame.
When creating the TOC the first frame keep with the chapter name. the problem it's that the insertion of the TOC are inserted in the second frame and not in the thrid frame.
After TOC update:
What is the name of the paragraph format for the Table of Contents paragraph? Make sure the paragraph format doesn't end with TOC because any paragraphs with that suffix in the paragraph format name get deleted when you generate the table of contents.
Frameexpert you got it! The suffix was the issue here!
You could also make "Table of Content" static text in a disconnected background frame which is not copied as part of the table of contents feature, but which is always there.
Of course the question is why this paragraph text was not copied. frameexpert suggested a possible cause.