Finder not responding to [NSRunningApplication activateWithOptions] on secondary display

Question

I’m trying to bring the Finder window to front:

NSRunningApplication *finder = [NSRunningApplication runningApplicationWithProcessIdentifier:finderPID];
[finder activateWithOptions:NSApplicationActivateIgnoringOtherApps];

This works on the primary, built-in display. But on my external display, the Finder window doesn’t get focus after calling -activateWithOptions. Is that the expected behaviour? Is it a bug?