[Bug]: Using autocomplete to add a handle to the end of a non-last line removes the next line break

[LukaszH77]

Describe the bug

Using autocomplete to add a handle on the end of a non-last line removes the line break if the lines were separated by two line breaks. If there is only one line break, the first word of the next line is also deleted.

Steps To Reproduce

1. Write more than one line of text.
2. Go back to the end of the non-last line.
3. Use the autocomplete suggestions to add a user handle.
4. The next line break has been removed.

Logs and/or Screenshots

Instance Backend

Mastodon

Operating System

openSUSE Tumbleweed

Package

Flatpak

Troubleshooting information

os: GNOME 45 (Flatpak runtime)
prefix: /app
flatpak: true
version: main-e2e4d23 (development)
gtk: 4.12.1 (4.12.1)
libadwaita: 1.4.0 (1.4.0)
libsoup: 3.4.2 (3.4.2)
libgtksourceview: 5.9.0 (5.9.0)

Additional Context

No response