Changing the Client Certificate in the Chrome Extension

I have the Postman Chrome extension installed on my computer. We have a API for secure email that requires Mutual TLS. when I submit a POST using the API after restarting my computer, it prompts me for a client certificate. Upon selecting the correct client certificate, everything works correctly. The Subject CN of the client certificate is the email address of the user. When I want to test the system with a different email address, it tries to use the certificate already cached for the previous email. It doesn’t prompt for a different client certificate. The only way I have found to change the client certificate to match the new email address is to either clear the browser cache or to restart my computer. Is there another way to choose a different client certificate?