Agent response duplicated in email

Hi, 

I have created a Copilot Studio Flow which has 3 agents. 2 agents do some research in parallel, I catch the results in 2 different string variables and hand the variables over to a third agent. The third agent should merge both variables, format them and hand them over to "Send Email". In the email body I add the output of agent 3.

The workflow itself works. But I always have the complete email body text twice in the email received by the recipients. Where is the duplicate of the agent output coming from? 

I have this issue also when I add the agent response of agent 1 and agent 2 directly to the "send email" node.

Does anyone have an idea? Would be great to get feedback. Appreciate it.

Thanks!