Error on activating SumoMe plugin on freshly deployed WP droplet

Hi guys, I made a fresh Wordpress droplet. I didn’t do any changes. The Wordpress version is 5.8 and upon activating the SumoMe plugin, it throws the following error :

Plugin could not be activated because it triggered a fatal error. Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, non-static method WP_Plugin_SumoMe::activate_SumoMe_plugin() cannot be called statically in /var/www/html/wp-includes/class-wp-hook.php:303 Stack trace: #0 /var/www/html/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters() #1 /var/www/html/wp-includes/plugin.php(470): WP_Hook->do_action() #2 /var/www/html/wp-admin/plugins.php(193): do_action() #3 {main} thrown in /var/www/html/wp-includes/class-wp-hook.php on line 303

Steps I’ve tried :

1. Thinking it might be a corrupt installation, it reinstalled the droplet but that doesn’t solve.
2. I also tried updating the Ubuntu packages, didn’t help.