Here is the long version: you most probably have the line $Configuration['Garden']['MobileInputFormatter'] = 'Wysiwyg'; in your conf/config.php, but it must be $Configuration['Garden']['MobileInputFormatter'] = 'Rich';. Since there is a JavaScript error by now, JS stops working as expected and that's why arbitrary annoyances might occur.
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Here is the long version: you most probably have the line
$Configuration['Garden']['MobileInputFormatter'] = 'Wysiwyg';in your conf/config.php, but it must be$Configuration['Garden']['MobileInputFormatter'] = 'Rich';. Since there is a JavaScript error by now, JS stops working as expected and that's why arbitrary annoyances might occur.