Hello
I'm new to Office 365 and I'm trying to increase the productivity of the team I manage and improve the way we interact with our clients on a more collaborative approach.
I tried to look up for a solution to my problem in the community but i could not find it and any help is appreciated.
We work on B2B and we sell machinery to our clients thus projects
To test the framework I created a team and group with some colleagues and some other people outside of my company domain without Office 365 acting as client and vendor (therefore a team and a group of people with same company domain and other outside of it)
I created sharepoint site when I created an Issue list to share and collaborate on.
I create a Project Plan in Planner with same users as the team above described.
I created a workflow that everytime an new item is added to the sharepoint Issue list, a mail it is sent to people in the team and mainly to the mail / person is responsible for. At the same time the same item is added to Planner related Bucket
Although the mail is automatically generated with the workflow I have an error related to the part in Planner. The task in planner bucket is not created.
This is the error in the workflow.
Referenced User or Group (same mail added in the item in share point) is not found.

Can anyone recommend me how to do it?
below the workflow

franco