Index: wp-content/themes/twentytwentythree/theme.json
===================================================================
--- wp-content/themes/twentytwentythree/theme.json	(revision 54300)
+++ wp-content/themes/twentytwentythree/theme.json	(working copy)
@@ -539,7 +539,11 @@
 			},
 			"core/quote": {
 				"border": {
-					"width": "1px"
+					"left": {
+						"color": "inherit",
+						"style": "solid",
+						"width": "1px"
+					}
 				},
 				"elements": {
 					"cite": {