An SFDC Website field is populated with "HTTPS://GOOGLE.COM". When viewing the field's value in the UI, the result is displayed as "http://HTTPS://GOOGLE.COM". The following text: "http://" is added to the beginning of a URL online in CRM.
Standard SFDC Website field expects the URL to start with a lowercase "https://" or "https://".
When populating the standard Website field, be sure https:// is lowercase.
CRM Help Documentation: N/A