No, that issue with Wfinity is a different problem and isn't cause by something you did.

There have been issues reported with the idm.xfinity.com server and it appears that Comcast/Xfinity has forgotten to update/renew the certificate for this domain. You can contact Comcast and point them to the Qualys SSL Report for idm.xfinity.com.

• https://www.ssllabs.com/ssltest/analyze.html?d=idm.xfinity.com
• https://www.ssllabs.com/ssltest/analyze.html?d=idm.xfinity.com&s=96.99.230.105
• https://www.ssllabs.com/ssltest/analyze.html?d=idm.xfinity.com&s=2001%3a558%3afeed%3adc%3a0%3a0%3a0%3a18

Try to login via this page:

• https://login.xfinity.com/login

See a thread like this one

• /questions/1420928 unable to sign into Xfinity for email

More:

• https://support.mozilla.org/en-US/search/?w=2&product=firefox&q=field%3Acontent%3A%7Bcomcast+email%7D+range%3Aquestion_created%3Agte%3Anow-30d%2Fd

For background: Firefox may be the last browser that does a real-time check for whether a site certificate has been revoked, so it is the first browser affected by this kind of problem.

Firefox doesn't have a way to exempt only one site from the revocation check; it is all sites or no sites. For that reason, if you are okay with checking your email in another browser for a while, that probably is safest, rather than having us describing how to turn off certificate revocation checking globally.