fix sessionInput button show/hide visibility

stylesheets/_session.scss

@@ -314,6 +314,11 @@ $session_message-container-border-radius: 5px;
     margin-top: 13.5px;
   }
 }
+
+.hidden {
+  visibility: hidden;
+}
+
 .input-with-label-container {
   height: 46.5px;
   width: 280px;

ts/components/session/SessionInput.tsx

@@ -59,12 +59,12 @@ export class SessionInput extends React.PureComponent<Props, State> {
           }}
         />
         <button
-          onClick={() =>
+          onClick={() => {
             this.setState({
               forceShow: !this.state.forceShow,
-            })
-          }
-          className={classNames(enableShowHide ? '' : '')}
+            });
+          }}
+          className={classNames(enableShowHide ? '' : 'hidden')}
         >
           SHOW
         </button>