Dependency chain: Parent1Component -> SomeTableComponent -> SlideToggleComponent -> MatSlideToggleModule Parent2Component -> SomeTableComponent -> SlideToggleComponent -> MatSlideToggleModule Parent component #1 @Component({ selector: 'app-parent1', standalone: true, imports: [ SomeTableComponent, <------------ CommonModule, FormArrayPipe, FormsModule, MatButtonModule, MatDividerModule, MatFormFieldModule, MatIconModule, MatInputModule, ReactiveFormsModule, ], templateUrl: './parent1.component.html', styleUrl: './parent1.component.scss', }) export class Parent1Component { } Parent component #2 @Component({ selector: 'app-parent2', standalone: true, imports: [ SomeTableComponent, <------------ CommonModule, GridItemComponent, NavBarComponent, NavBarV2Component, MatTabsModule, ], templateUrl: './parent2.component.html', styleUrls: ['./parent2.component.scss', '../mat-tabs.scss'], }) export class Parent2Component implements AfterViewInit, OnDestroy, CanComponentDeactivate {} Both my parent1 & parent2 use a shared table (SomeTableComponent) SomeTableComponent controller: @Component({ selector: 'app-some-table', standalone: true, imports: [ CommonModule, ClipboardIconComponent, MatExpansionModule, MatTooltipModule, MatIconModule, MatButtonModule, MatProgressSpinnerModule, PaginationComponent, SlideToggleComponent, <-- problematic GetDatePipe, GetTimePipe, ], templateUrl: './some-table.component.html', styleUrls: ['./some-table.component.scss'], }) export class SomeTableComponent implements OnInit {} SomeTableComponent template: ...html stuff... <app-slide-toggle ></app-slide-toggle> SlideToggleComponent controller: @Component({ selector: 'app-slide-toggle', standalone: true, imports: [MatSlideToggleModule], templateUrl: './slide-toggle.component.html', styleUrl: './slide-toggle.component.scss', }) export class SlideToggleComponent { } SlideToggleComponent html: <mat-slide-toggle bunch of directives... > </mat-slide-toggle> When using the SomeTableComponent in my Parent2Component, everything worked. When I tried adding SomeTableComponent to my Parent1Component, I get an angular application error: some-random.component.ts:14 Uncaught TypeError: Cannot read properties of undefined (reading 'SlideToggleComponent') at Module.SlideToggleComponent (some-random.component.ts:14:25) at <static_initializer> (some-table.component.ts:50:5) at 63805 (some-table.component.ts:30:55) at __webpack_require__ (bootstrap:19:1) at 5347 (some-other-random-component.component.ts:30:24) at __webpack_require__ (bootstrap:19:1) at 186 (index.ts:45:104) at __webpack_require__ (bootstrap:19:1) at 25940 (some-random.component.ts:14:25) After some testing, I noticed that if I comment out the SlideToggleComponent from my SomeTableComponent, it works. What I don't understand is why this works when my SomeTableComponent was only being used in my Parent2Component, but as soon as it's added to Parent1Component, it can't resolve SlideToggleComponent. Continue reading...