MAX 10 - Erase CFM sector - IP states "successful" yet sector not erased

I use DE10-Lite board which has same FPGA model as your project for testing your code. But before I use MAX1000 (has 10M08) and 10M04 FPGAs and success the RSU operation (erase, rewrite and switch images). May be you can try different FPGA model as you said.

As comes to "fake" an erase, unfortunately it is impossible. Because when erasing, writing "1" to all bits and you can not change "0" to "1" manually. You can just change "1" to "0". But you can try page erase operation. May be it works.