I do see a fatal error when I open the plugin and look at the connection details. On the backend, I get this:
AH01071: Got error ‘PHP message: PHP Fatal error: Uncaught Error: Call to a member function geAH01071: Got error ‘PHP message: PHP Fatal error: Uncaught Error: Call to a member function get_error_message() on array in {{host path}} wp-content/plugins/fluent-smtp/app/Services/Mailer/Providers/Gmail/Handler.php:310\nStack trace:\n#0?{{host_path}}/wp-content/plugins/fluent-smtp/app/Http/Controllers/SettingsController.php(223): FluentMail\\App\\Services\\Mailer\\Providers\\Gmail\\Handler->getConnectionInfo()\n#1 [internal function]: FluentMail\\App\\Http\\Controllers\\SettingsController->getConnectionInfo()\n#2?{{host_parth}}/wp-content/plugins/fluent-smtp/includes/Core/Container.php(507): call_user_func_array()\n#3?{{host_parth}}/wp-content/plugins/fluent-smtp/includes/Core/Container.php(633): FluentMail\\Includes\\Core\\Container->call()\n#4?{{host_parth}}/wp-content/plugins/fluent-smtp/includes/Core/Container.php(502): FluentMail\\Includes\\Core\\Container->callCla…’, referer: {{domain}}/wp-admin/options-general.php?page=fluent-mail