Until version 69, I was happily working with two client certificates for the same server using *Select one automatically* option; Firefox was choosing the correct certificate for either of the two server-side applications. Since version 70, it doesn't seem to do so anymore. It seems to choose a random(?) certificate out of the two which makes one application work, the other one fails with an SSL error: either SSL_ERROR_UNKNOWN_CA_ALERT or SSL_ERROR_CERTIFICATE_UNKNOWN_ALERT. When selecting *Ask you every time* option, I can select the appropriate certificate and connect to both application. However, it's not remembering the corresponding certificate and after restarting Firefox, it will suggest the first certificate again (which is correct for one application but wrong for the other). This is another indication that Firefox is not able anymore to choose an appropriate certificate when requested by the server. Did the *Select one automatically* option or underlying certificate selection mechanisms change with version 70? How exactly is the certificate selection *supposed to work*? Which parameters of the server's certificate request are used to select the appropriate certificate from my local database? Is there some debug logging I can turn on to further investigate this problem? Thanks for any ideas! -Marc