If your HTML output includes material that precedes the TOC (a cover page, splash screen, or title), by default DITA2Go suppresses the page break between that material and the TOC. This is because if you use the default values for both of the following settings:
[Chunking]
SplitTopicFiles = Yes
DisableChunking = No
you might be left with output that provides no way to navigate from the preceding material to the TOC.
To keep the page break between the preceding material and the TOC:
[Contents]
; KeepTOCWithTitlePage = Yes (default, suppress page break between
; title page and TOC) or No (keep page break)
KeepTOCWithTitlePage = No
Specify KeepTOCWithTitlePage=No if the title content already includes a link to the TOC.