TC-866 single vs dual channel ddr4 memory

LFine

I bought an Aspire TC-866-UR11, and am getting it set up.  I have two matching ddr4 memory sticks (2x8gb), Samsung M378A1K43CB2-CTD, the model that came stock with the system, but the memtest86 tool I ran to verify that the ram is good, is telling the memory is in single channel 64-bit mode.  I have the latest bios version from Acer's website, the bios has nearly no settings to adjust.  I would imagine this system supports dual channel memory?  I do not have a second set of ddr4 memory to swap in to test.  Is there something additional I can try with the Acer desktop?  I'd certainly like to have the extra performance out of the system.  Thanks

Leostat

Are both sticks showing as installed in task managerl, and what does CPUz say about the memory?