Ion-popover inline 'is not a known element'

I am attempting to use an ion-popover inline as the documentation states

here is the code that i have

..Excluded for simplicity
<ion-popover [isOpen]="isLoading">

I have other ionic components on this same view like ion-refresher and ion-list and ion-item. But ion-popover is causing the build to fail

I have also used the ion-popover in other places within the app but i am using the controller method. In this case i would like to use it as inline.

usually, this happens when there is something wrong in the .module
for example, if you load some custom component before the other modules are loaded.

check that the order is similar to my example

this is what my module looks like… but still same issue

import { FormsModule } from '@angular/forms';
import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';
import { StoreModule } from '@ngrx/store';
import { reducer } from './state/schedule.reducer';
import { EffectsModule } from '@ngrx/effects';
import { ScheduleEffects } from './state/schedule.effects';
import { DatePipe, CommonModule } from '@angular/common';
import { IonicModule } from '@ionic/angular';
const scheduleRoutes: Routes = [];

  imports: [
    StoreModule.forFeature('schedule', reducer),
  providers: [
export class ScheduleModule {}

do this:
create a new page and try to use your ion-popover code there.
If it works on the new page, you can begin to import component by component and module by module: eventually, you will find which is the broken one.