After receiving my doctoral degree from Kyoto University, I started working as an assistant professor at Seikei University. I removed the previous email address from Kyoto University and added a new one from Seikei University to my SIAM membership account. One year after starting the job, I subscribed to SIAM J. Optim. and SIAM J. Control Optim. because Seikei University does not subscribe to those journals. However, despite completing the payment, I was unable to access the latest papers in the journals I subscribed to.
I sent an email to SIAM customer service to resolve this issue. After three weeks of interaction with them, they found that the removal of the old email address caused my subscriptions not to be linked to either account.
Be careful when removing your initial email account after creating it.