Is it moving over the rest but not cutting? It’s also not cutting the wide parts fully. I know you said you adjusted the depth of cut but it really looks to me that the software thinks the top of the board is higher up than it is. Maybe an issue with your Z settings, the bit height is not where the machine thinks it is.
Your vcarve depth of cut in the simulation is likely determined by the edges of the lettering and the angle of the bit. I.e. It won’t go deeper if that would put it beyond the width of the letter stroke. So the simulation is likely showing you the right thing. If you want deeper vcarve use a lower angled v-bit. I.e. a 60º will carve deeper than a 90º.
So my specific problem was user error and probing for z again fixed things. That being said I did not understand the idea that a vcarve is a path between two lines as you mentioned above.