Index: wp-content/themes/twentytwenty/assets/css/editor-style-block.css
===================================================================
--- wp-content/themes/twentytwenty/assets/css/editor-style-block.css	(revision 53058)
+++ wp-content/themes/twentytwenty/assets/css/editor-style-block.css	(working copy)
@@ -658,6 +658,10 @@
 	line-height: 1.25;
 }
 
+.editor-styles-wrapper .wp-block-quote cite {
+	font-style: normal;
+}
+
 .editor-styles-wrapper .wp-block-quote p {
 	color: inherit;
 	font-weight: 400;