Migration from a server to another keeping the same domain name Jetpack is lost

Hi,

I have migrated the data from a website from A to B.

Host “A” specification :

• Multisite WordPress installation.
• WP 5.9.4 on the client website.
• Client website connected with Jetpack.

New Host “B” specification :

• Single WordPress installation.
• WP 6.4.1

The website have a new IP adress now and use the same domain name.

But, in the WordPress.com/Jetpack administration page, I see 2 sites with the same domain name. If I choose one or the other, JetPack can’t communicate with the new host, says that my WordPress is a multisite and the version of WordPress is like the configuration of the “A” host.

Newsletter subscription doesn’t synchronised.

How to pu together the data ?

I have disable/enable the jetpack plugin, uninstall and reinstall it wihtout success.
I have tested xml rpc and I have the message : XML-RPC server accepts POST requests only.

Need help please 🙂