Nios V: niosv-download reports "no harts found" on Agilex 5 board

Greetings,

This seems to be a reset issue. The Reset Release IP is missing from your platform. You may refer to the Nios V application note: https://www.intel.com/content/www/us/en/docs/programmable/784468/current/an-985-processor-tutorial.html
You can follow the steps in 1.2.1 section (1.2.1.1.2.4. Adding Reset Release Intel® FPGA IP).

Furthermore, you may refer to the design examples available for Agilex 5 development kit:

1- Agilex™ 5 - Hello World on Nios® V/g Processor Design Example

2- altera-fpga/agilex5e-nios-ed: Nios V Processor example designs targeting Altera Agilex 5 Development Kits

Thank you,

Fawaz.