Description:
When attempting to copy-paste multi-line blocks of text, I noticed that LibreOffice Writer did not always preserve the bold-face properties of text on the last line. To illustrate with an example, let's assume in the example text below that upper-case letters represent bolded text while lower-case letters:

```
SOME BOLDED TEXT: some normal text
SOME OTHER BOLDED TEXT: some other normal text
```

Copying such text in LibreOffice Writer and pasting somewhere later would ***sometimes*** remove the bold from the last line:

```
SOME BOLDED TEXT: some normal text
some other bolded text: some other normal text
```

(the bolding is removed from the last line).

Steps to Reproduce:
1. Open a new LibreOffice Writer document.
2. Write multiple contiguous lines of text (e.g. line-after-line, no newline characters separating different lines).
3. Bold some of the characters in the last line.
4. Copy the entire block of text.
5. Paste the text somewhere after the copied text.
6. (Occasionally) Observe that the last line lost its bolding. You may need to do this repeatedly since it is not consistent.

Actual Results:
The last line of text that I pasted lost its bolding.

Expected Results:
The last line of text that I pasted should have kept its bolded characters in bold.


Reproducible: Sometimes


User Profile Reset: Yes

Additional Info:
Version: 24.2.7.2 (X86_64) / LibreOffice Community
Build ID: 420(Build:2)
CPU threads: 12; OS: Linux 6.11; UI render: default; VCL: gtk3
Locale: en-US (en_US.UTF-8); UI: en-US
Ubuntu package version: 4:24.2.7-0ubuntu0.24.04.3
Calc: threaded