*Failed* h.265 Render from large comp in After Effects

Hi,

I am having issues trying to render to h.264 a 4416x1780 comp from After Effects.

A few months ago I was able to do this (with h.264) before but now it limits my render to 4k max (4096px)

Tried h.265 (i was under the impression that this codec was meant for larger sizes) but the render doesn't even start. It just goes to "failed" and displays a "!" symbol.

I know can render in ProRes and convert with Handbrake but I was wondering if anyone has any pointers to do it directly in Adobe Media Encoder without the extra steps. As I need the final product to be an h264 or h265 mp4 file.

PS I am running the latest versions of all the Adobe products as of this date, with terabytes of free space, on an iMac Pro.

Thank you!