SERVMOD is missing pull-up OR PRESENCE DETECT function is absent?
preusming that SERVMOD is also the function "presence detect" noted on this https://ohwr.org/project/diot-crate-hw/wikis/uploads/94755f3c4581ea438a639a672a8a92dd/backplane_v2_topology_scaled.png
it needs a default pull up. The text box on sheet 21 would also need updating.
to be clarified if these are the same function or not