Thumbnails do not appear

Hello,
I have a problem with your “network posts extended” plugin as I also installed the “Network Media Library” plugin (https://github.com/humanmade/network-media-library) in order to make the Media available in all the sites of the network.
The media are entered in the table of blog # 1
By inserting an article in Blog 4 in the “4_postmeta” table, the following records are created:
id post_id meta_key meta_value

707 354 _thumbnail_id 480

711 355 _wp_attached_file 2022/01 / prototipo-formula-1-2022.jpg

Record 480 does not exist in the “4_post” table as it is created in the “post” table (of blog n. 1)
Thus the image does not appear.