store.load is not invoking the api call specified in the proxy after doing filtering

I am creating the store and applying filter on it. After applying filter, I am loading the store. As part of loading the store the api specified in the proxy is not getting run.
Here is the code for creating the store and applying filter and loading the store.

    var fields = classConfigModel.getFields();
    if (fields) {
      var storeConfig = {
        fields: fields,
        proxy: {
          type: 'ajax',
          url: wsUrl,
          timeout:40000,
          extraParams: {
            wsId: wsId,
            initRecache: this.INIT_RECACHE
          },
          reader: {
            totalProperty: 'totalCount',
            type: 'json',
            root: this.STORE_ROOT_PROPERTY
          }
        },
        autoLoad: true
      };
      if (this.IS_INFINITE_GRID) {
        storeConfig.buffered = true;
        storeConfig.leadingBufferZone = 100;
        storeConfig.pageSize = 200;
      }
      var sortConfigStore = classConfigModel.getSortConfigStore();
      if (sortConfigStore) {
        storeConfig.sorters = sortConfigStore.getSortersArray();
      }
      var store = Ext.create(this.MODULAR_BASE_STORE, storeConfig);


      if (!store) {
        this.logError('store is undefined');
      }
      else {
        // We want to monitor when the store's data changes, so we can update the info area
        this.addEventListener(store, 'datachanged', this.onStoreDataChanged, this);

        store.on('filterchange', this.onStoreFilterChanged, this);
        this.store = store;
      }

      if ( wsId === 'device') {
        console.log("Coming to apply filter to the store");
        store.clearFilter(true);
        store.filter([
          {filterFn: function (item) {
                return item.get("environment") != 'DELETE' && item.get("environment") != 'Decommission';
              }}
        ]);
        store.load();
      }


    }
  },