Restore snapshot from another cluster (7.8 to 8.5)

I have a question/problem.
I have a GCP bucket with tons of snapshots taken from a kibana 7.8, A new kibana has been deployed in another cluster v8.5, that kibana has been connected to the GCP bucket where the old kibana snapshots are being stored, but even when the kibana connects succesfully to the bucket it doesn't detect any snapshots.

Am I missing something? What should I take into consideration in this case?
is this accomplishable?

Have you tried to query the snapshots repository with the Kibana Dev tools? A query like this should list the available snapshots in your repository

GET _snapshot/{repository_name}/*

If that query does not return any data then this feels more an issue with the repository configuration and it should be forwarded to the Elasticsearch forum. If what you see in the query results is not the same presented by the Kibana Stack Management interface then that seems more like a bug that would need further exploration.

According to the documentation, snapshots created with 7.8 should be compatible with 8.5.

yes.. and nothing came up

If your query does not return any results then I'd suggest to review the settings of your repository to confirm everything is correct (permissions, authentication, paths, etc).

For anyone interested, the problem was the version of Elasticsearch used, a 7.8v was deployed and snapshots were found.