Question about Samsung SEK-3500U/ZG UHD Evolution Kit

No, your HU should support HDCP 2.2 on the HDMI3 connection (labelled MHL). I have the UE65HU8280 and this is the case there. Otherwise, just take a look at the operating instructions. The codec mentioned by the previous speaker is irrelevant for devices connected to HDMI.

I don't know if this helps, but I bought the box for my UE65F9000 (2014) because Netflix only came in HD, not UHD. After that it worked. The old box can't handle H.265/HEVC, which Netflix uses to compress UHD content. It's quite possible that Swisscom handles this in the same way.