The Force has an aspect, somewhat separate from its other aspects, responsible for the existence of life and consciousness. Not necessarily life force or life energy or whatever, but just the spark of being. This is how droids can be sentient living beings even though they don’t otherwise register in the Force. This is how ysalimiri and other creatures that block the Force can do so without harming themselves or life around them. This is how the Jedi Exile survived and continued living while cut off from the Force, and also how they got it back. I haven’t read all the Yuuzhan Vong books but I imagine this would also apply to them.