Javascript – Why isnt my mongodb profile saving to database?

The main issue is my code saves the first time around but then will not work no matter what I try. It should be simple to save to the database and it is the first time but after that the database refuses to save the data. I do not believe this is an issue of validation but rather something with the save method.

I am expecting the profile database to add another profile. However it only does this for the first profile added. After that it always produces some error. I have tried different post requests, i have tried deleting all elements in the database.

I am given the following error:

    Profile not created
    MongoServerError: E11000 duplicate key error collection: test.profiles index: email_1 dup key: { email: null }
    .../message_stream.js:33:9) at writeOrBuffer (internal/streams/writable.js:358:12) {
      index: 0,
      code: 11000,
      keyPattern: { email: 1 },
      keyValue: { email: null },
      [Symbol(errorLabels)]: Set(0) {}
    }

I am trying to save a profile to MongoDB database using mongoose with the following code:

    // create new profile
    router.post('/create', async (req, res) => {
    
        const profile = new Profile({
            user: {
                username: req.body.username,
                email: req.body.email,
                password: req.body.password1,
            },
            trips: [],
        });

        try {
            const prof1 = await profile.save();
            console.log(`created profile ${profile.user.username}`);
            console.log(req.params);
            return res.json(prof1);
        } catch (err) {
            console.log("Profile not created");
            console.log(err)
            return res.send(err);
        }
    });

Here is my profile Schema:

    const profileSchema = new Schema({
        user: {
            username: {
                type: String,
                required: [true, "Add a username"],
                unique: true,
            },
            email: {
                type: String,
                required: [true, "Add an email"],
                unique: true,
            },
            password: {
                type: String,
                required: [true, "Add a password"],
            },
        },
        trips: [{
            type: Schema.Types.ObjectId,
            ref: "Trip",
        }],
    }, {timestamps: true});