I updated to patch 1.4 and my sneak damage multiplier changed from 5.4x which was wrong to 4.8 but that is still wrong I have, Cloak and Dagger Ninja rank 3 and Ninja rank 3 and all silenced weapons it should be either 4.2x, 4.9x, 5.95x, or 6.3x depending on whether they are based on base character damage (just added together 3.5+.5+.2=4.2) , base sneak damage of 2.0 (3.5+1+.4=4.9) ninja as the base (3.5+1.75+.7=5.95) or based on the new total for each (3.5+1.75+1.05=6.3)

Looks like no one cares about this "fix" in Bethesda. "It just works" is enough for them.

For now i'm using "Mister Sandman Unfixed" and "Ninja fix" mods from Nexus, multiplier is 6.3x with them, working like a charm.