if your iso is near 99% ready i would try this:
start an NEW removing process with an untouched iso (so like if you start from 0)
than load your preset file (your 99% .wccf),
and deselect all Services and components at Remove, let WinReducer only remove FEATURES
than test your iso if vpn works
if yes -> load that iso without the Features and load again your 99% preset, now deselect all Services again and about 50% of components at remove.
and so on and so on,
if vpn does not work with your test iso, get one step back and try to find what component is causing your problem