Yes, my batocera is connected via Ethernet. I’ve connected through other services with success.
Only the Themes Downloader Windows doesn’t show any themes files to download.
I’ve done what you indicated, I connected via via SSH, ping batocera.org with success and curl -k https;//batocera.org/themes.php with success as well.
I think it could be any misconfigured config file, don’t you think?
But I don’t have any idea where and which file is.