### Steps to reproduce

<br>

1. Set up a meeting series with e.g. 5 meetings and add _User A_ as participant

2. open the first meeting

3. Navigate back to the meeting template for this meeting series

4. Add a new participant _User B_ to the series


### What is the buggy behavior?

<br>

* _User B_ will not be added as a participant to the already opened first meeting


### What is the expected behavior?

<br>

1. Begin of the insertionThe participation dialog in meeting templates is extended, so that you can choose to make change to all open meetings, instead of the template

1. When selected, addingEnd of the insertion Begin of the deletion AddingEnd of the deletion a user as a participant to the template of a meeting series also add them as a participant to already open meetings of that series. Begin of the insertion


End of the insertion Begin of the deletion


End of the deletion ### Environment information

_Please check and fill out the following details to help us identify in what versions and distributions of OpenProject the error occurs_

**OpenProject installation type**

* Hosted cloud edition


**OpenProject version**

_17.0.2_

**Browser**

* [ ] Chrome
* [ ] Firefox
* [ ] Safari
* [ ] Mobile Safari
* [x] Other (Vivaldi)

**Operating System**

* [x] Windows 11 :-(
* [ ] Mac OS X
* [ ] Mobile iOS
* [ ] Mobile Android
* [ ] Linux (please specify distro)
* [ ] Chrome OS
* [ ] Other (please specify)

**Language**

_EN/DE_