findOne is not a function mongoose

I know it is an old question and I am aware of the usage that I'm not suppose to call findOne function on instance of model, instead on the model itself.

Here is my corporation.model.js:

const mongoose = require('mongoose');
const corporationSchema = new mongoose.Schema(
  {
    name: {
      type: String,
      required: true,
      trim: true,
    },
    logo: {
      type: String,
      required: true,
    },
    description: {
      type: String,
      required: false,
      trim: true,
    },
    companyType: {
      type: String,
      required: true,
    },
    code: {
      type: String,
      required: true,
      immutable: true,
      unique: true,
    },
  },
  { timestamps: true }
);

corporationSchema.statics.fetchOneWithAssociations = async function fetchOneWithAssociations(
  id
) {
// func definition
};

corporationSchema.statics.findByName = async function findByName(text) {
// func definition
};
module.exports = mongoose.model('Corporation', corporationSchema);

and my event.model.js:

const mongoose = require('mongoose');
const { of } = require('await-of');
const Corporation = require('./corporation.model');

const EventSchema = new mongoose.Schema(
  {
    title: { type: String, required: true },
    subtitle: { type: String },
    corporationId: {
      type: mongoose.Schema.Types.ObjectId,
      ref: 'Corporation',
      required: true,
    },
  },
  { timestamps: true }
);

EventSchema.statics.findByCorporationId = async function findByCorporationId(
  corporationId,
  filterQuery,
  limit,
  offset,
  sort
) {
  try {
    let corporation = {};
    let logoErr = {};
    let totalEvents = 0;
    let events = [];

    if (corporationId) {
      [totalEvents, errCount] = await of(
        this.count({ corporationId, ...filterQuery })
      );

      [events, err] = await of(
        this.find({ corporationId, ...filterQuery })
          .sort(sort)
          .limit(limit)
          .skip(offset)
      );
      console.log('Corporation', Corporation);
      [corporation, logoErr] = await of(
        Corporation.findOne({ _id: corporationId }, 'logo')
      );

      if (err || errCount) {
        throw err;
      }
    }

    return {
      events,
      count: totalEvents,
      logo: corporation.logo,
    };
  } catch (e) {
    throw e;
  }
};

EventSchema.statics.exceptByCorporationId = async function exceptByCorporationId(
  corporationId,
  filterQuery,
  limit,
  offset,
  sort
) {
 // func definition
};

module.exports = mongoose.model('Event', EventSchema);

line console.log('Corporation', Corporation); prints an object i.e. {}. Ok I understand, it is a problem but here is my question. why? I mean it seems like I have created my model correctly. Didn't I. Why I'm getting my model as instance instead of my model class itself.