The numbering bullets of imported PPT changed to same number

I have a PPT file. Some pages are using numbering bullets. After I imported the PPT file to Captivate, the numbering bullets changed to same number.

1) for example, if the page has 1,2,3,4,5, the converted captivated file looks like 1,2,3,4,5 in the edit view. However, when I preview it, all bullets changed to 1,1,1,1,1. After i published it, the bullets are still 1,1,1,1,1.

2) Another case, my peer imported the ppt from his pc. The captivate file can publish properly as 1,2,3,4,5 initially. However, after I generate more audio from the text for each page, the issue appears again.

What's wrong?