Hi @talithislilith,
you can try to press the ‘Reset Let’s Encrypt’ link in the top right corner of the Really Simple SSL Let’s Encrypt wizard, that should provide you with a new certificate.
We are aware of a bug in the plugin where resetting does not seem to work correctly on some environments. This is something we will investigate and develop a fix for in a future version of Really Simple SSL. As a workaround, you can temporarily enter a different e-mail address in the Let’s Encrypt e-mail field. That will force the wizard to create a new certificate.