When you've pressed and held the DC button for 2 seconds, you then need to press the yellow pan up shoes down button (below the DC button) to disengage the MCB. If you look at the top left of the main panel, you'll see 2 yellow lights and a red one below it. When you press for DC, the top light goes out and the bottom one kicks in for the MCB. If you then press the pan up shoes down button (maybe twice), the MCB light (bottom one) will go out and the line volt light (top one) will come back on.
Glad I could help. I had the same issue the first few times I ran the 395 on SEHS. Once you've done it a few times, it becomes second nature and you can do it without thinking.