@mabeljh did you ever manage to make any progress with this? I think the preferred way to access the camera on 64 bit OS is with libcamera but that doesn’t have support for any of the custom Arducam modifications.
Have you tried to recompild the source code following the userguide? https://github.com/ArduCAM/MIPI_Camera/tree/master/RPI/lib/aarch64#readme