Like the title says, I'm trying to use the "Default Resolution" on the rop image output node in houdini 21 and it doesn't seem to be working.

It's exporting the image at the res of the node I have setup in the COP path.

From my understanding it should be using the "Default Resolution" when I have it checked within the node.

N_Mateja
...It's exporting the image at the res of the node I have setup in the COP path.
From my understanding it should be using the "Default Resolution" when I have it checked within the node.

from help:

Sets the context option for default_xres and default_yres. This is the size of layers that don’t have an explicit size set.
The default is 1024×1024.

which sounds consistent with what you are describing
essentially only layers that don't have explicit resolution within COPnet will get the specified default one, and when unchecked this default is 1024x1024