Index: wp-content/themes/twentynineteen/style-editor.css
===================================================================
--- wp-content/themes/twentynineteen/style-editor.css	(revision 55900)
+++ wp-content/themes/twentynineteen/style-editor.css	(working copy)
@@ -550,7 +550,7 @@
 h4:lang(th),
 h5:lang(th),
 h6:lang(th), figcaption:lang(th),
-.gallery-caption:lang(th), .editor-post-title__block .editor-post-title__input:lang(th), .block-editor-default-block-appender textarea.block-editor-default-block-appender__content:lang(th), .wp-block-paragraph.has-drop-cap:lang(th):not(:focus)::first-letter, .wp-block-table:lang(th), .wp-block-cover h2:lang(th),
+.gallery-caption:lang(th), .editor-post-title__block .editor-post-title__input:lang(th), .block-editor-default-block-appender textarea.-default-block-appender__content:lang(th), .wp-block-paragraph.has-drop-cap:lang(th):not(:focus)::first-letter, .wp-block-table:lang(th), .wp-block-cover h2:lang(th),
 .wp-block-cover .wp-block-cover-text:lang(th), .wp-block-button .wp-block-button__link:lang(th), .wp-block-quote cite:lang(th),
 .wp-block-quote footer:lang(th),
 .wp-block-quote .wp-block-quote__citation:lang(th), .wp-block-pullquote[data-type="core/pullquote"] .wp-block-pullquote__citation:lang(th),
@@ -1605,3 +1605,8 @@
   padding-right: 0;
   width: 100%;
 }
+
+/* Post Author Block  */
+.wp-block-post-author__avatar img {
+    border-radius: 100%;
+}
\ No newline at end of file