I have developed a solution inside our Dev Environment , and i shared a canvas power apps with some users and they were able to access the app which is connected to SharePoint.
then i created a new Prod environment, and i defined this security group so only admins can edit the environment and i shared the power apps with the related users (the users are not part on the below security group), as follow:-

but when the users try to access the power apps inside the above Prod environment they will get this error message:-

now i remove the security group from the environment setting and i define it as None, as follow:-

but still the users are getting the same error.. any advice?