In my code I have to do, for example:

<script setup lang="ts">
	import {
		IonContent,
		IonHeader,
		IonList,
		IonPage,
		IonTitle,
		IonToolbar,
		IonCheckbox
	} from '@ionic/vue';
</script>

<template>
	<IonPage>
		<IonHeader>
			<IonToolbar>
				<IonTitle>
					Test
				</IonTitle>
			</IonToolbar>
		</IonHeader>

		<IonContent>
			<IonList>
				<IonCheckbox @["ion-change"]="console.log"></IonCheckbox>
			</IonList>
		</IonContent>
	</IonPage>
</template>

with "ion-change" being specified literally that way, to listen to said event. Neither v-on:ionChange nor v-on:ion-change (with shorthands et cetera) are working anymore.

I noticed this after a dependency update that brought me to version 8.4.3 from version 8.4.1 - and also it went unnoticed because I personally only seldom use ionChange, relying most of the times on v-models.

(My project is https://github.com/NyaomiDEV/Ampersand if you want to know more)

Also, I was able to reproduce it minimally on StackBlitz: https://stackblitz.com/edit/vj18czas?file=src%2FApp.vue