I am attempting to add my gmail email address as the secondary email but I am getting the error "Secondary email must be different than your account email". The primary account is an msn.com address so there is no reason that I can think of that a gmail address should not be accepted, other than a bug or malicious code. I have tried this with the Firefox browser (version 90.0.1 (64-bit)), with the Chrome browser (Version 92.0.4515.107 (Official Build) (64-bit)) and Edge (Version 91.0.864.71 (Official build) (64-bit)); the results are the same in all three. I have included the raw troubleshooting data from the Firefox browser. I first tried this on an existing account. After reading some responses to similar questions in this forum I created a new account that has never had the gmail address associated with it. I do not believe that the old account that I deleted had ever had the gmail account associated with it either.