Well, let's look at the facts:
- The DQ67EP board was released in Q1 of 2011.
- Windows 10 was not released until Q2 of 2015.
- Windows 10 is not listed as a supported O/S for this board.
- According to the BIOS release notes, nothing major has been done to the BIOS since 2012.
Based upon this, I would be willing to bet that the board's Secure Boot feature has never been tested with Windows 10.
Bottom line, if it didn't work with the DH61DL -- and you were doing it properly -- it's unlikely that it will work with the DQ67EP. Further, since both of these boards are in the end-of-life and end-of-interactive-support states -- and Intel has exited the Desktop Boards business altogether -- if the feature is broken, there is absolutely zero chance of it being fixed (there's simply no one left to do it).