I observed if e.g. i assign shift + w/a/s/d for doging while w/a/s/d is assigned for walking / strafing it always doges, no matter if i have shift pressed or not. Same happens for any other assignment using shift (probably also with other modifiers). Another example is shift + R for incubator and R for reloading.
In the menu it shows me the correct assignment but it seems the modifier is ignored in the game itself.