Debian 10 Upload too Slow

Greetings I already found this Question here (https://unix.stackexchange.com/questions/536555/debian-10-very-slow-upload/543926#543926) but it didnt resolved my issue. For my Network the Uploadspeed is too slow. So I hope someone can help me please. cat /etc/debian_version 10.1 ethtool eth0 Settings for eth0: Supported ports: [ TP AUI BNC MII FIBRE ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supported pause frame use: Symmetric Receive-only Supports auto-negotiation: Yes Supported FEC modes: Not reported Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Advertised pause frame use: Symmetric Receive-only Advertised auto-negotiation: No Advertised FEC modes: Not reported Speed: 1000Mb/s Duplex: Full Port: MII PHYAD: 0 Transceiver: internal Auto-negotiation: off Supports Wake-on: pumbg Wake-on: d Current message level: 0x00000033 (51) drv probe ifdown ifup Link detected: yes speedtest-cli Retrieving speedtest.net configuration... Testing from Internetprovider (xx.xxx.xxx.xxx)... (changed by Caaruzo) Retrieving speedtest.net server list... Selecting best server based on ping... Hosted by Company (City) [6.09 km]: 12.472 ms (changed by Caaruzo) Testing download speed................................................................................ Download: 91.21 Mbit/s Testing upload speed...................................................................................................... Upload: 3.70 Mbit/s 3.70 Mbit/s is very slow. when i try another machine on same network i get 34.05 Mbit/s Does someone have an idea what could cause this issue? I am Using onboard LAN. Mainboard is A320M-DGS done iperf3 test now iperf3 -c 192.168.178.32 Connecting to host 192.168.178.32, port 5201 [ 5] local 192.168.178.40 port 43810 connected to 192.168.178.32 port 5201 [ ID] Interval Transfer Bitrate Retr Cwnd [ 5] 0.00-1.00 sec 114 MBytes 952 Mbits/sec 0 3.01 MBytes [ 5] 1.00-2.00 sec 111 MBytes 933 Mbits/sec 0 3.01 MBytes [ 5] 2.00-3.00 sec 112 MBytes 943 Mbits/sec 0 3.01 MBytes [ 5] 3.00-4.00 sec 111 MBytes 934 Mbits/sec 0 3.01 MBytes [ 5] 4.00-5.00 sec 111 MBytes 933 Mbits/sec 0 3.01 MBytes [ 5] 5.00-6.00 sec 112 MBytes 944 Mbits/sec 0 3.01 MBytes [ 5] 6.00-7.00 sec 111 MBytes 933 Mbits/sec 0 3.01 MBytes [ 5] 7.00-8.00 sec 111 MBytes 933 Mbits/sec 0 3.01 MBytes [ 5] 8.00-9.00 sec 112 MBytes 942 Mbits/sec 0 3.01 MBytes [ 5] 9.00-10.00 sec 111 MBytes 935 Mbits/sec 0 3.01 MBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.00 sec 1.09 GBytes 938 Mbits/sec 0 sender [ 5] 0.00-10.04 sec 1.09 GBytes 934 Mbits/sec receiver Ive also recognized, it happens to all my machines that run under Debian 10.1. Also Virtual ones. With machines with Version 9.11 this problem don't exist.