Bug?? Bullet Points in Paragraph styles turn off and bullets become normal text

Hi everyone,

I'm not really sure how to describe what happened, as this is a very strange error to me.

Basically, I typing a paragraph using a paragraph style with bullet points. When I hit return (to go to the next line) I noticed that my bullet point was not appearing. 

It appears that somehow the style changed. The paragraph style (Bulles and Numbering) and the "List Type" option was changed to "None".

What is stranger is that the bullets weren't gone from my document, they were all still there, but they had all become disassociated with the style. So visually, it appeared that nothing had changed, but in reality none of the actual bullet points were styled with the paragraph style anymore.

As I mentioned a very weird error. Has anyone incountered this before