So I had to re-program the remote.
Hold down the button closest to the display on the Ossc while powering off and on. Then follow the instructions on the OSSCs display.
I can confirm that 1080i passthrough isn’t working correctly, at least with GT4. I can switch between 2x and passthrough and there is no change to the image. I’m not sure why this happens. I will try doing some reboots later, but for now 1080i passthrough looks exactly the same as 2x mode on PS2 GT4.
I’m using a Sony 950g with an OSSC hardware version 1.6