Its undocumented in the release notes (as far as I know), but in our testing, we found that Roku firmware versions < 7.0 do not support Server Name Identification (SNI) for https. It looks like this was added as a feature of 7.0.
Our service is currently paying an extra monthly fee to have Cloudfront use dedicated IPs, so that devices with 6.2 can play the videos.
It appears that there are three holdout Roku devices that do not have 7.0 and I was wondering if there are plans to transition them soon or if they are going to be stuck on 6.2 for a while. (end goal for me is to drop the dedicated IP requirement)
The builds are: 6.2 3675 (TCL RokuTV) 6.2 4218 (Insignia RokuTV) (thanks to MatroxRT) 6.2 4295 (LG RokuTV)