Steps to reproduce

1. Click "new message"
2. Enter a few lines, e.g.:

test
test

test

3. Close the compose window (the message is saved as a drafts)
4. Go to "Drafts" folder
5. Open the draft just created

Expected behavior

The draft appears with the original text:

test
test

test

Actual behavior

All the line breaks have been replaced with spaces

test test test

Mail app version

5.1.1

Nextcloud version

30.0.11 Enterprise

Mailserver or service

No response

Operating system

No response

PHP engine version

None

Nextcloud memory caching

No response

Web server

None

Database

None

Additional info

Tested with Firefox 143.0.4 on Ubuntu 24.04