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 +539,8 @@
 			},
 			"core/quote": {
 				"border": {
-					"width": "1px"
+					"width": "0 0 0 1px",
+					"style": "solid"
 				},
 				"elements": {
 					"cite": {