Create and Save .docx in Writer then reopen and Bulleting is incorrect

I created and saved a docx file in Writer with a bulleted list.

I then Saved the file. I reopened it and found that my bulleted list was now just a series of spaces used to indent and either question marks representing the bullets, or no character representing the bullets. What happened here? Has this happened to anyone else? How can I fix this or prevent this from happening again?

What happened here?

You are the only one who can answer because you are the only one who was there. We can only make good guesses if you read these guidelines and ask a good question.

How can I fix this or prevent this from happening again?

Most probably, your problem is about compatibility. NEVER work in foreign file formats. Otherwise, losses of formatting and/or data are almost inevitable.

My recommendation is to (carefully) design and use styles rather than ad hoc formatting.