diff --git a/projects/igniteui-angular/src/lib/grids/selection/selection.service.ts b/projects/igniteui-angular/src/lib/grids/selection/selection.service.ts
index aedfaee3f31..0d35bad66d1 100644
--- a/projects/igniteui-angular/src/lib/grids/selection/selection.service.ts
+++ b/projects/igniteui-angular/src/lib/grids/selection/selection.service.ts
@@ -439,7 +439,7 @@ export class IgxGridSelectionService {
 
     /** Select all rows, if filtering is applied select only from filtered data. */
     public selectAllRows(event?) {
-        const addedRows = this.allData.filter((row) => !this.isRowSelected(this.getRecordKey(row)));
+        const addedRows = this.allData.filter((row) => !this.rowSelection.has(this.getRecordKey(row)));
         const selectedRows = this.getSelectedRowsData();
         const newSelection = this.rowSelection.size ? selectedRows.concat(addedRows) : addedRows;
         this.indeterminateRows.clear();
@@ -616,10 +616,8 @@ export class IgxGridSelectionService {
         if (this.allRowsSelected !== undefined && !newSelection) {
             return this.allRowsSelected;
         }
-        const selectedData = new Set(newSelection ? newSelection : [...this.rowSelection]);
-        const allData = this.getRowIDs(this.allData);
-        const unSelectedRows = allData.filter(row => !selectedData.has(row));
-        return this.allRowsSelected = this.allData.length > 0 && unSelectedRows.length === 0;
+        const selectedData = new Set(this.getRowIDs(newSelection || this.rowSelection));
+        return this.allRowsSelected = this.allData.length > 0 && this.allData.every(row => selectedData.has(this.getRecordKey(row)));
     }
 
     public hasSomeRowSelected(): boolean {
@@ -639,13 +637,16 @@ export class IgxGridSelectionService {
         if (this.areEqualCollections(currSelection, newSelection)) {
             return;
         }
+        
         const args: IRowSelectionEventArgs = {
             owner: this.grid,
             oldSelection: currSelection,
             newSelection,
-            added, removed,
-            event, cancel: false,
-            allRowsSelected: this.areAllRowSelected(newSelection.map(r =>  this.getRecordKey(r)))
+            added,
+            removed,
+            event,
+            cancel: false,
+            allRowsSelected: this.areAllRowSelected(newSelection)
         };
 
         this.grid.rowSelectionChanging.emit(args);