hmm, well the 'net' numbers are the wire connections, and I'm not sure why they would disappear.
if you are using object search paths (which of course your not ) then it could you have changed your path since you last used it?
or object has changed such that an inlet/outlet has been removed.
don't think this is likely on factory objects, but perhaps if you have changed your sub patches?
would need to see the patch to be sure whats going on .
what you could try is saving the patch (as new patch so you don't loose original), its possible when you do this it will be missing some wires. (actually already missing in the UI)