https://github.com/rustdesk/rustdesk/issues/298

src/ui/common.css

@@ -156,9 +156,7 @@ header caption {
     top: 0;
     padding: 0 10px;
     width: 22px;
-    height: *;
     position: absolute;
-    margin: 0;
     color: black;
     border: none;
     background: none;