Fix an edge case where it might be possible for email content to have similar post-slug

MAILPOET-5949

packages/js/email-editor/src/components/template-select/select-modal.tsx

@@ -47,8 +47,7 @@ export function SelectTemplateModal( {
 	const hasTemplates = templates?.length > 0;
 
 	const handleTemplateSelection = ( template: TemplatePreview ) => {
-		const templateIsPostContent =
-			template.template.type === 'mailpoet_email';
+		const templateIsPostContent = template.type === 'mailpoet_email';
 
 		const postContent = template.template as unknown as EmailEditorPostType;
 

packages/js/email-editor/src/components/template-select/template-list.tsx

@@ -46,7 +46,7 @@ function TemplateListBox( {
 		<div className="block-editor-block-patterns-list" role="listbox">
 			{ templates.map( ( template ) => (
 				<div
-					key={ template.slug }
+					key={ `${ template.slug }_${ template.id }` }
 					className="block-editor-block-patterns-list__list-item"
 				>
 					<div