Activation error in multisite

Hi there,

In multisite when I try to activate plugin, I face this errors:

[03-Mar-2021 14:00:18 UTC] PHP Fatal error:  Uncaught Error: Access to undeclared static property: Helpful\Core\Helpers\Database::$table_feedback in /var/www/vhosts/x.com/httpdocs/wp-content/plugins/helpful/core/helpers/class-database.php:59
Stack trace:
#0 /var/www/vhosts/x.com/httpdocs/wp-content/plugins/helpful/core/helpers/class-values.php(208): Helpful\Core\Helpers\Database::table_exists_or_setup('helpful')
#1 /var/www/vhosts/x.com/httpdocs/wp-content/plugins/helpful/core/helpers/class-optimize.php(31): Helpful\Core\Helpers\Values::table_exists('helpful')
#2 /var/www/vhosts/x.com/httpdocs/wp-content/plugins/helpful/core/modules/class-maintenance.php(126): Helpful\Core\Helpers\Optimize::optimize_plugin()
#3 /var/www/vhosts/x.com/httpdocs/wp-includes/class-wp-hook.php(287): Helpful\Core\Modules\Maintenance->maintenance_after_update('')
#4 /var/www/vhosts/x.com/httpdocs/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(NULL, Array)
#5 /var/www/vhosts/x.com/httpdocs/wp-includes/plugin.php in /var/www/vhosts/x.com/httpdocs/wp-content/plugins/helpful/core/helpers/class-database.php on line 59

Regards