Widget error on dashboard – Fatal error: Uncaught TypeError: gmdate():

Hi, after activating the plugin and debug mode I found error in WordPress dashboard widget area.

 ! ) Fatal error: Uncaught TypeError: gmdate(): Argument #2 ($timestamp) must be of type ?int, string given in /data/Local-Sites/bnkh/app/public/wp-admin/includes/dashboard.php on line 1017
( ! ) TypeError: gmdate(): Argument #2 ($timestamp) must be of type ?int, string given in /data/Local-Sites/bnkh/app/public/wp-admin/includes/dashboard.php on line 1017
Call Stack
#	Time	Memory	Function	Location
1	0.0001	364136	{main}( )	.../index.php:0
2	0.2132	15256016	wp_dashboard( )	.../index.php:203
3	0.2153	15260496	do_meta_boxes( $screen = 'dashboard', $context = 'side', $data_object = '' )	.../dashboard.php:274
4	0.2157	15279040	wp_dashboard_site_activity( '', ['id' => 'dashboard_activity', 'title' => '?????????', 'callback' => 'wp_dashboard_site_activity', 'args' => []] )	.../template.php:1445
5	0.2164	15285832	wp_dashboard_recent_posts( $args = ['max' => 5, 'status' => 'publish', 'order' => 'DESC', 'title' => '???????? ????????', 'id' => 'published-posts'] )	.../dashboard.php:946
6	0.2191	15558760	gmdate( $format = 'Y-m-d', $timestamp = '??????????' )	.../dashboard.php:1017

Here is the image of the error.

gmdate function has variable $timestamp and that is causing the issue.

Why it is happening, could you check it please.