ember: computed propertied | ember-macto-helper/computed vs @ember/objects

I am moving away from ember-macro-helpers/computed in my project and starting using computed from '@ember/object' I have following code

rowData: computed('addEndpointsData', function () {
    const addEndpointsData = this.addEndpointsData
    const data = this._getEndpointGridData(addEndpointsData)

    if (data) {
      this.endpointRows.push(data)
      this.set('endpoints', this.endpointRows)
      return this.endpoints
    }
  }).readOnly(),


  endpointSummaryMsg: computed('rowData', 'endpoints.[]', function () {
    const endpoints = getWithDefault(this, 'endpoints', [])
    return `${endpoints.length} Endpoint(s)`
  }).readOnly(),

And in my test case, I am setting addEndpointsData so that rowData gets re-computed and in turn endpointSummaryMsg.

describe('when add endpoint data is not empty', function () {
        beforeEach(function () {
          component.setProperties({
            endpoints: [],
            tmpEndpoints: [],
            actionType: ACTION_ENUM.ADD,
            endpointRows: [],
            addEndpointsData: {
              serviceIntent: {
                properties: {
                  endpoints: [{
                    settings: {
                      role: 'UNI'
                    }
                  }],
                  serviceType: 'EVPL'
                }
              }
            },
            onEndpointChange () {}
          })
        })

        it('should display right summary msg for one rows', function () {
          expect(component.get('endpointSummaryMsg')).to.eql('1 Endpoint(s)')
        })
      })
    })

It was working fine with macro-helper, but with ember/objects, this seems to break and rowData is not re-computed, hence testcase gets 0 Endpoint(s)

I have tried following . set(addEndpointsData, 'serviceIntent', {....}) . component.notifyPropertyChange('addEndpointsData')

but nothing seems to work. What could be the issue here?