Hi @james-janetech 
Thank you for your feedback 
According to this thread and this one, there can be only one production environment at the same time on a project, and we do not support production project deletion.
Could you provide the name of the environment you want to remove? (Is it the one named “production” or “integration”?). I can manually set it to a “remote” environment (instead of a production one). Then I could switch the other one to “production”.
Thanks!