Document font change from tools>options>writer>basic fonts

Windows 7, LibreOffice 7.5.6.2, format ODT (added: tools> in the sequence)
I am not using styles: I made the change under: tools>options>writer>basic fonts
I assumed that changes made here are for the default settings for new documents, but it surprised me when it changed the existing open/current document.

I want to confirm it is a bug before posting to bugzilla.
Sometimes things like this are considered “that’s just the way it is…”
If this is normal then I just have to make changes in options without an open document.
Thank, Tracey

Is setting the default font option “settings” supposed to change all the fonts in an open document or is this a bug?
I had to reset LibreOffice back to factory defaults in order to resolve an issue.
I was re-setting my desired options as I found them to set them back to the way I wanted them.
When setting the default font to Liberation Sans while I had a document open and it changed all the fonts in the document to Liberation Sans (there was Liberation Sans, Serif, etc.).

Please advise.
Thanks, Tracey

Please, improve your question (= reopen it and modify it; don’t use a comment) to provide more details: OS name, LO version, save format. How do you format your documents? With styles or manually? Have your changed all the variants or only Default?

How was the open document styled? How did you apply Liberation Serif? Where was it used?

I think this is expected if you are using styles, it is rather the point of styles that they can be changed through the document by changing the style. Default Paragraph inherits from Basic Fonts - Default, Body Text inherits from Default Paragraph; Heading inherits from Basic Fonts - Heading.

If you break the link for the font attribute by setting a font in a paragraph style then it won’t change if the document is open. The same for Direct Formatting

If the document is closed then it is not affected by the change; just like receiving a document from somebody else with different settings appears the same as on their computer assuming you both have same fonts.

Bugzilla tdf#158013 has been confirmed, but resolution unknown.
Please stand-by
Thanks, Tracey