I've managed to find the issue.
The problem seems to be related to Windows iperf3 implementation. I've uploaded a real file from LAN -> NAS with Nextcloud and I achieved the 10Gb speed.
In case anyone faces a similar issue, test on Linux and on Windows do a real test.
The problem seems to be related to Windows iperf3 implementation. I've uploaded a real file from LAN -> NAS with Nextcloud and I achieved the 10Gb speed.
In case anyone faces a similar issue, test on Linux and on Windows do a real test.