Grammar highlighting (I think) is happening but is there more info about why it's highlighted anywhere Writer?

[Lido]

I just pasted some text into a new writer doc and a couple of sections are highlighted in white (theme is Light Gray). There don’t seem to be any spelling errors in the sections, but maybe the highlight is showing me grammar issues or punctuation? Is there any way to see more about why it chose to highlight or anything like that? Right click doesn’t seem to bring anything up. Bringing the text into a unicode editor shows that there are “no-break spaces” in each of the highlighted blocks of text if that helps in any way (there is one no-break space before “late” and one after “great” in the screen-shot below).

Version: 26.2.0.3 (AARCH64)
Build ID: afbbd0df0edb6d40b450b0337ac646b0913a760c
CPU threads: 12; OS: macOS 15.7.4; UI render: Skia/Metal; VCL: osx
Locale: en-US (en_US.UTF-8); UI: en-US
Calc: threaded

[EarnestAl]

There is no sample to check but I would guess that the pasted text had some direct formatting or character style for white highlight.
Select the text and click Format > Clear direct formatting (Ctrl+M). Does the white highlighting disappear? If not, with the text still selected, double click No Character Style in the Sidebar > Styles > Character Styles.
.
You can paste as unformatted text to remove any styling from say a web page or another document.
.
You might find the Writer Guide useful as a reference, download from English documentation | LibreOffice Documentation - LibreOffice User Guides

[Lido]

ctrl-M gets rid of the white, but also changes the font. In case you missed my edit, both sections have no-break spaces in them so I’m guessing that’s the issue. I don’t know if the author intended those to be there or not, so I’m just going to leave them in case it’s intentional.

[EarnestAl]

@Lido

ctrl-M gets rid of the white, but also changes the font

@Lido

I don’t know if the author intended those to be there or not

So your document is entirely direct formatted. That makes for a difficult workflow. I have to assume that the author did not intend to create the issue but didn’t know how to remove the grey highlight once it was applied except by replacing it with a white highlight.
.
Given that you don’t want to correct the issue at its root then you are left with using Clone Formatting brush to copy the direct formatting from the grey highlighted text to over the white highlighted text.