Fatal error on Activation

I would love to switch to SEOPress but I can’t get this extension to work. There has been a bigger update at mainWP and this plugins last Update is more than a month ago. Maybe it is related.

<code>Fatal error: Uncaught TypeError: Cannot access offset of type string on string in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/seopress-for-mainwp/inc/class-main.php:234 Stack trace: #0 /var/www/vhosts/example.com/httpdocs/wp-includes/class-wp-hook.php(308): SEOPress\MainWP\Main->remove_mainwp_post_types() #1 /var/www/vhosts/example.com/httpdocs/wp-includes/plugin.php(205): WP_Hook->apply_filters() #2 /var/www/vhosts/example.com/httpdocs/wp-content/plugins/wp-seopress/src/Services/WordPressData.php(41): apply_filters() #3 /var/www/vhosts/example.com/httpdocs/wp-content/plugins/wp-seopress/src/Actions/Admin/ManageColumn.php(41): SEOPress\Services\WordPressData->getPostTypes() #4 /var/www/vhosts/example.com/httpdocs/wp-includes/class-wp-hook.php(308): SEOPress\Actions\Admin\ManageColumn->setup() #5 /var/www/vhosts/example.com/httpdocs/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters() #6 /var/www/vhosts/example.com/httpdocs/wp-includes/plugin.php(517): WP_Hook->do_action() #7 /var/www/vhosts/example.com/httpdocs/wp-settings.php(617): do_action() #8 /var/www/vhosts/example.com/httpdocs/wp-config.php(91): require_once('...') #9 /var/www/vhosts/example.com/httpdocs/wp-load.php(50): require_once('...') #10 /var/www/vhosts/example.com/httpdocs/wp-admin/admin.php(34): require_once('...') #11 {main} thrown in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/seopress-for-mainwp/inc/class-main.php on line 234</code>

Tested with PHP 8.0 and 8.1, same errors. Also used most recent MainWP version and the beta with 8.1 compatibility.