Aggiornamento, è appena andato via il tecnico di OF che ha montato l'ONT della Nokia ecco gli speed test:
tiberio@homeserver:~$ speedtest -s 3667
Speedtest by Ookla
Server: TIM SpA - Milan (id: 3667)
ISP: Dimensione
Idle Latency: 18.78 ms (jitter: 0.28ms, low: 18.52ms, high: 18.99ms)
Download: 2096.90 Mbps (data used: 3.1 GB)
41.61 ms (jitter: 6.80ms, low: 17.89ms, high: 327.31ms)
Upload: 431.37 Mbps (data used: 240.5 MB)
20.14 ms (jitter: 0.93ms, low: 17.72ms, high: 32.96ms)
Packet Loss: 0.0%
Result URL: https://www.speedtest.net/result/c/d05be1cd-a665-4edf-a370-53fe145a7e01
tiberio@homeserver:~$ speedtest1
Speedtest by Ookla
Server: EOLO - Milan (id: 11427)
ISP: Dimensione
Idle Latency: 18.10 ms (jitter: 0.20ms, low: 17.92ms, high: 18.52ms)
Download: 2070.28 Mbps (data used: 2.5 GB)
42.65 ms (jitter: 6.61ms, low: 17.48ms, high: 335.14ms)
Upload: 453.91 Mbps (data used: 822.1 MB)
18.53 ms (jitter: 0.61ms, low: 17.15ms, high: 32.39ms)
Packet Loss: 0.0%
Result URL: https://www.speedtest.net/result/c/57c13bd5-2eb2-4774-a0e6-a9fd2e3137d8
tiberio@homeserver:~$ speedtest2
Speedtest by Ookla
Server: CWNET - Milan (id: 1434)
ISP: Dimensione
Idle Latency: 18.10 ms (jitter: 0.49ms, low: 17.93ms, high: 18.78ms)
Download: 1978.29 Mbps (data used: 2.5 GB)
28.73 ms (jitter: 3.81ms, low: 17.85ms, high: 48.27ms)
Upload: 446.15 Mbps (data used: 800.3 MB)
18.52 ms (jitter: 0.79ms, low: 17.19ms, high: 32.52ms)
Packet Loss: 0.0%
Result URL: https://www.speedtest.net/result/c/dc05d232-b905-4dcb-becf-1134c0bccb22
tiberio@homeserver:~$ speedtest3
Speedtest by Ookla
Server: Wind Tre - Milano (id: 27363)
ISP: Dimensione
Idle Latency: 19.42 ms (jitter: 0.44ms, low: 19.23ms, high: 19.80ms)
Download: 1850.64 Mbps (data used: 2.3 GB)
38.74 ms (jitter: 3.80ms, low: 19.57ms, high: 63.30ms)
Upload: 439.50 Mbps (data used: 243.4 MB)
19.24 ms (jitter: 6.20ms, low: 18.30ms, high: 267.94ms)
Packet Loss: 0.0%
Result URL: https://www.speedtest.net/result/c/af90e41a-e884-4a93-b5d8-8f8272247dc3
Finalmente tutto risolto, grazie a Dimensione @giusgius