非常抱歉！我相信這是一個最近出現的迴歸問題（regression，即過去幾週內引入的新錯誤）。有幾個變通方法應該可以讓它正常運作：
1. 請嘗試在「Body」分頁中關閉「Prevent Orphan Words」，看看空格是否會恢復：
2. 但如果那不起作用，請將這一行加入 Advanced --> ptxprint-mods.tex 檔案中：
\def\BookChapSeparator{\ }
Our apologies! I believe that this is a recent regression (a new bug introduced in the last few weeks). There are a couple of work-arounds that should get it working properly:
1. See if turning off "Prevent Orphan Words" on the Body tab brings the space back:
2. But if that doesn't work, then add this line to the Advanced --> ptxprint-mods.tex file:
\def\BookChapSeparator{\ }
機器翻譯自 English
