PS4 Pro HDR+ VR Processor box?

Hi guys I picked up a PSVR not long after release and then the PS4 pro just after Christmas. I picked up a 4k TV recently to complete th gaming set up I've always dreamed of. However, it set up fine until it came to HDR. HDR works fine when I use the PS4 pro hdmi directly to the TV but not at all when I use the processor box with the vr. Does this mean I need to buy a new hdmi to replace the original vr one or can the processing unit just not handle HDR?

Thanks for any advice in advance.