I have a GTX 1080 which has an HDMI 2.0b port and I'm using a HDMI 2.1 cable but the HDMI 1.4a ports on my TV limits the bandwidth to the HDMI 1.4 specification. HDMI 1.4 only goes up to 4k 30Hz. As I said in the title I'm using Nvidia custom resolution.
This is my TV: TCL 32" Class 3-Series FHD LED Roku Smart TV - 32S327 | TCL USA
This is my TV: TCL 32" Class 3-Series FHD LED Roku Smart TV - 32S327 | TCL USA