Have metric render 0

app/src/interfaces/_system/system-field/system-field.vue

@@ -12,7 +12,7 @@
 		:model-value="value"
 		:disabled="disabled"
 		:items="selectItems"
-		:placeholder="t('select_a_field')"
+		:placeholder="placeholder || t('select_a_field')"
 	/>
 </template>
 

app/src/panels/metric/index.ts

@@ -94,6 +94,7 @@ export default definePanel({
 				options: {
 					collectionField: 'collection',
 					allowPrimaryKey: true,
+					placeholder: '$t:primary_key',
 				},
 				width: 'half',
 			},

app/src/panels/metric/metric.vue

@@ -72,7 +72,7 @@ export default defineComponent({
 		);
 
 		const displayValue = computed(() => {
-			if (!metric.value) return null;
+			if (metric.value === null || metric.value === undefined) return null;
 
 			if (props.options.abbreviate) {
 				return abbreviateNumber(metric.value, props.options.decimals);