Ok I understand now.
As you mention it must be a software issue then.
Another thing would be to try contact the DVR manufacturer for a firmware update to see if that fixes the issue, or at least ask them about it.
Also you might be able to sell it to someone that doesn't need that feature (its actually rarely used) and then buy a DVR that has that working feature.
Thanks, I wrote, they don't answer, they are in China.
God bless
Jim
Really sorry to hear this...This is really bad. Hope you will not have prejudice against Chinese company because of this. So anyway, choose the supplier carefully. It is not easy to find customers, neither is to find a good supplier