changes not saved - format Times New Roman

changes not saved - format Times New Roman

Hi there,

the following often happens:
I edit a document - make some changes: formatting text, adding Titel header format etc.
I save my online work, close the file and afterwards edit the document:

then the formatting is not saved, everything has changed to Times New Roman.
Sometimes the title is OK but all normal text has changed
<span style="font-family: 'Times New Roman'; font-size: 12pt;">

This is very annoying

(originally i copied from a Word doc, and thought that this was the problem, but it also occurs when copying from Notepad)

Any ideas??
thx