Hi Charles, kilroyscarnival, Guessed, and all others who ended up scratching their heads.

I am really sorry for the wild goose chase.

I just found out that the recipient had edited the file not on the laptop but on an Android mobile.

I have told her never to edit any MS Word files on the mobile phone.

She took a shortcut without realizing the consequences.

Still, I am relieved that I understand why the custom styles got lost.

@kilroyscarnival

All my body text styles are based on my base style “My_00_Body_base” so that any change to the base style propagates to all the body text styles. There are other styles for titles, headings, etc. that are not based on that base style.