PHP Fatal error

Hi, after moving my website to wordpress.com hosting I get this error. Custom posts are no accessible if Gutenslider is active. If I deactivate it they become accessible in the backend, while they are never accessible on the front-end. This issue never occured with previous hostings.

PHP Fatal error: Uncaught TypeError: array_key_exists(): Argument #2 ($array) must be of type array, null given in /wordpress/core/6.5.3/wp-includes/block-supports/custom-classname.php:48
Stack trace: 0 /wordpress/core/6.5.3/wp-includes/class-wp-block-supports.php(119): wp_apply_custom_classname_support(Object(WP_Block_Type), NULL) 1 /wordpress/core/6.5.3/wp-includes/class-wp-block-supports.php(176): WP_Block_Supports->apply_block_supports() 2 /srv/htdocs/wp-content/plugins/gutenslider/src/blocks/gutenslider/block-front.php(581): get_block_wrapper_attributes() 3 /wordpress/core/6.5.3/wp-includes/class-wp-block.php(463): eedee_gutenslider_dynamic_render_callback(Array, ‘\n<div class=”sw…’, Object(WP_Block)) 4 /wordpress/core/6.5.3/wp-includes/blocks.php(1705): WP_Block->render() 5 /wordpress/core/6.5.3/wp-includes/blocks.php(1743): render_block(Array) 6 /wordpress/core/6.5.3/wp-includes/class-wp-hook.php(324): do_blocks(‘<!– wp:paragra…’) 7 /wordpress/core/6.5.3/wp-includes/plugin.php(205): WP_Hook->apply_filters(‘<!– wp:paragra…’, Array) 8 /wordpress/core/6.5.3/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php(1865): apply_filters(‘the_content’, ‘<!– wp:paragra…’) 9 /wordpress/core/6.5.3/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php(569): WP_REST_Posts_Controller->prepare_item_for_response(Object(WP_Post), Object(WP_REST_Request)) 10 /wordpress/core/6.5.3/wp-includes/rest-api/class-wp-rest-server.php(1230): WP_REST_Posts_Controller->get_item(Object(WP_REST_Request)) 11 /wordpress/core/6.5.3/wp-includes/rest-api/class-wp-rest-server.php(1063): WP_REST_Server->respond_to_request(Object(WP_REST_Request), ‘/wp/v2/Profiles…’, Array, NULL) 12 /wordpress/core/6.5.3/wp-includes/rest-api.php(555): WP_REST_Server->dispatch(Object(WP_REST_Request)) 13 /wordpress/core/6.5.3/wp-includes/rest-api.php(2922): rest_do_request(Object(WP_REST_Request)) 14 [internal function]: rest_preload_api_request(Array, ‘/wp/v2/Profiles…’) 15 /wordpress/core/6.5.3/wp-includes/block-editor.php(753): array_reduce(Array, ‘rest_preload_ap…’, Array) 16 /wordpress/core/6.5.3/wp-admin/edit-form-blocks.php(77): block_editor_rest_api_preload(Array, Object(WP_Block_Editor_Context)) 17 /wordpress/core/6.5.3/wp-admin/post.php(187): require(‘/wordpress/core…’) 18 {main}

thrown in /wordpress/core/6.5.3/wp-includes/block-supports/custom-classname.php on line 48