### Steps to reproduce

1. Login as a user with all meetings and WP permissions

2. Go to any WP

3. Go to Meetings tab

4. Click Add to Meeting

5. Choose an 'older' meeting Begin of the insertion(from before April 2025)End of the insertion Begin of the deletion (unsure how old, just not a fresh one)End of the deletion


### What is the buggy behaviour?

* In Section drop down, Series backlog shows as 'Untitled section'


### What is the expected behaviour?

1. In Section drop down, Series backlog shows as 'Series backlog'


### Screenshots and other files

drop down in WP tab

<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/782001/content">

actual meeting

<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/782002/content">

### Environment information

**OpenProject version**

Core build

[01cdde53fbe71fa80ec2a36ed4bb94523e884d10](https://github.com/opf/openproject/commits/01cdde53fbe71fa80ec2a36ed4bb94523e884d10)

Product version

[a58c32168495791b5944adbc577c4f0db8b1af03](https://github.com/opf/saas-openproject/commits/a58c32168495791b5944adbc577c4f0db8b1af03)

Core version

OpenProject 16.5.0

**Browser**

* [ ] Chrome
* [x] Firefox
* [ ] Safari
* [ ] Mobile Safari
* [ ] Other (please specify)

**Operating System**

* [x] Windows
* [ ] Mac OS X
* [ ] Mobile iOS
* [ ] Mobile Android
* [ ] Linux (please specify distro)
* [ ] Chrome OS
* [ ] Other (please specify)