Hi @da4396 - thanks for alerting us to a possible problem with the behaviour of \cl
I have tried to replicate the issue but am unable to get the same results. Could you clarify whether you have something following the \cl marker in the text.
Also, it is worth noting that you need to either use the settings at the end of the Body tab:
or direct markup in the text:
\c 1
\cl James Chapter 1
\p \v 1 baga....
but not both at the same time.
If you are still stuck, then please use the Create Archive… button on the Help tab and then send us the .zip archive file (to ptxprint_support @ sil.org) which will help us replicate and hopefully resolve the issue you’re facing. Preferably do this when just 1 (small) book is included - as we don’t need to see multiple books. [There could be something specific in the book introduction that is tripping it up - but that’s hard to guess without seeing the USFM data (which will get included in the archive)].