In fact the memory clocks don't change at all while in SLI, they are static. I will note is that the stock bios both of these cards came with runs at 6610 MHz not the 7010MHz it is supposed to be at stock (even while in 3D). The only time I have ever been able to get my memory clock to change was the initial install of Zotac Firestorm when I didn't have SLI running (it reverted to 0 after restart and was unchangeable from that point on). For MSI afterburner specifically I have all compatibility boxes ticked except constant voltage and have tried User and Kernel low-level access. I tried your values with no success, have disabled win10 automatic driver updates, wiped and reinstalled the drivers fresh with display driver uninstaller, uninstalled all overclocking software with IOBits, and then reinstalled one by one when the previous fails.

The only exception between these programs is that Precision X doesn't revert to 0 however it doesn't actually change the clock. I am also having this problem with MSI afterburner 4.1.1, EVGA Precision X, and Zotac Firestorm on Windows 10 with Nvidia driver 353.62 with two Zotac 980 TI in SLI (not AMP).

Memory clock msi afterburner