Attempting to save subdocument update, deletes the parent - mongodb

Question

I am attempting to save an update to my subdocument, but when I save the parent document disappears (thus loosing all the data including the update).
Here is my route:
router.put('/input/:parentid/:childid', urlencodedParser, function(req, res, next){
// Update Already Created Incident
async function update(id){
let checkedUnits = [];
let timeEntries = [];
recall = [];
units.forEach(unit => {
if(req.body[unit.id]){
checkedUnits.push(unit._id);
}
});
// console.log(personnel);
personnel.forEach(person => {
if(req.body[person._id]){
let PERSON = {person: {personId: person._id}}
recall.push(PERSON);
}
});
//===================FIND PARENT DOCUMENT===================================//
CallData.findOne({_id: id}, (err, doc)=>{
//====================TARGET CORRECT SUBDOCUMENT by id =====================//
subdoc = doc.incidents.id(req.params.childid);
//===========================UPDATE DOCUMENT=============================//
date = moment(req.body.dispatchDate).format('YYYY-MM-DD')
doc.date=date,
subdoc.incidentNumber = req.body.incidentNumber;
subdoc.callType = req.body.callType;
subdoc.times.dispatch = moment(req.body.dispatchDate).format('MM/DD/YY')+' '+req.body.dispatchTime;
subdoc.times.clear = moment(req.body.clearDate).format('MM/DD/YY')+' '+req.body.clearTime;
subdoc.address.placeName = req.body.locationName;
subdoc.address.streetAddress = req.body.streetAddress;
subdoc.address.apt = req.body.apt;
if(req.body.disposition !== "Choose..."){
subdoc.disposition.selected = req.body.disposition;
}
subdoc.disposition.typed = req.body.other;
subdoc.units = checkedUnits;
subdoc.recall = recall;
//==============Save Document===============//
doc.save(err=>{if(err){console.log(err)}); //<==============No error thrown here.
res.json(doc); //<==================Produces a correct json of the updated doc.
});
}
update(req.params.parentid);
});
Once the above runs on a document it disappears from the database. I am not sure why doc.save is deleting the doc.
I have tried using async/await, and CB. I am unsure how else to select the correct subdocument in the subdocument array. Mongoose's docs say to do the ```parent.sub.id(_id)`` to select it but I have a feeling this is where I am going wrong.
Thank you for any insight.
-Adam

Answer 1

The answer was here:
date = moment(req.body.dispatchDate).format('YYYY-MM-DD')
It was changing the date format and therefore I could not find my data, I thought it was being deleted it was not. Just being changed.
I have corrected the code to:
date = moment(req.body.dispatchDate).format('YYYY/MM/DD')
And now I it works beautifully.
Thanks for the help.