iPhone + Snapchat not working SSL?

I have mitmproxy installed fine on my MacBook Pro and also have downloaded the cert to my iPhone fine. I have been using it for some time and for most apps have no issue, however i have noticed snapchat and Facebook it doesn’t do anything, In snap chat is says could not refresh, and I’m thinking its doing to the SSL and I’m doing something wrong.

Hi,

you are running into certificate pinning: http://docs.mitmproxy.org/en/stable/certinstall.html#certificate-pinning