Hi and thanks for the reply,
The projector is not run through a slitter it is directly connected to 1 of the 2 HDMI outputs on the Marantz SR710 and the cable is a high quality cable that does support 18 Gb/s - I made sure of that because when I replaced my standard HD projector with the UHD65 the original cable did not work.
I only want the slitter for the kitchen t.v
I do think I know what the problem is though, because the projector plays downloaded content via USB and streams content (including 4K) though Netflix installed on the 4K bluray I have come to the conclusion that it is down to the cable but not because it can't push that much data - I recon its not getting the HDCP handshake quick enough.
This though I am not totally sure of, if the HDCP handshake is requested from the "Device/Bluray player" it doesn't explain it but if the HDCP handshake request appears from the 4K Bluray disc then it could.
I have some experimenting to do, play an old bluray that does not use HDCP (though that would not be conclusive as it will be pushing much less data so if the cable/signal was the issue this won't prove that theory, the other is to buy a cheap slitter that ignores the HDCP request
I'll keep on trying
PSB Imagine T3 - PSB Imagine S Surround - PSB Imagine C3 Centre - B K P12-300SB - B&W CCM65 x 4 in the ceiling - PSB CS1000 in the garden
Marantz SR7010 - NORD TWO ICE POWER 1200AS2 - Cambridge Audio A5
Sony Bravia KD65x8509C - Optoma UHD65 - PS4