Request particpant - user or customer permissions

[Eamonn Merrifield]

I have two active JSM projects.

On one project I have a team of agents that can easily add request participants from any customers that have been synced.

On the other I've a JSM agent who is a project admin who can't add participants to an issue. She can only add agents not customers. 

Using my credentials if I open a request within her project I can add participants from across the list of customers, but she can't - any clues? 

[Pedro Olmo]

Hello @Eamonn Merrifield ,

Can you check the following settings?  Products --> Jira Service Management --> Configuration

Also you can check the next configuration.

Jira project --> Access --> Customer permissions

Regards