System doesn't keep programming

Are you use .SOF to program? or .POF ?

I did what the directions stated and used the .SOF.

It's has two MAX10 EVA BOARDs, one is 10M08S, the other one is 10M50.

Programming FPGA by .SOF, than the code will lost after power lost. --> FPGA CAN'T remember any code when power lost.

Thanks much

This is the whole idea behind FPGAs. The configuration is stored in SRAM cells when you program the device. That's why the programming information must be stored on a non-volatile memory (usually flash) so the device gets programmed at power-up. MAX 10 devices include onboard flash so you can store your device configuration in the part of it called the CFM (configuration flash memory). See the MAX 10 trainings here and associated documentation: