Index: wp-content/themes/twentyseventeen/assets/css/editor-blocks.css
===================================================================
--- wp-content/themes/twentyseventeen/assets/css/editor-blocks.css	(revision 59114)
+++ wp-content/themes/twentyseventeen/assets/css/editor-blocks.css	(working copy)
@@ -831,3 +831,6 @@
 	font-weight: 800;
 	line-height: 1.5;
 }
+.editor-styles-wrapper .wp-block-pullquote[style*="font-size"] blockquote {
+       font-size: inherit;
+}
\ No newline at end of file
Index: wp-content/themes/twentyseventeen/style.css
===================================================================
--- wp-content/themes/twentyseventeen/style.css	(revision 59114)
+++ wp-content/themes/twentyseventeen/style.css	(working copy)
@@ -4375,3 +4375,6 @@
 		padding: 0;
 	}
 }
+.wp-block-pullquote[class*="-font-size"] blockquote{
+	font-size: inherit;
+}
\ No newline at end of file