Ok I'm still screwed with my network speed (ethernet gigabit).
I've been doing some iperf3 testing using my Synology NAS and NUC8 Catelina (both connected through ethernet in my home network)
Result when nas is server and nuc8 is client (= very good):
[ 5] 0.00-1.00 sec 109 MBytes 913 Mbits/sec
[ 5] 1.00-2.00 sec 111 MBytes 934 Mbits/sec
[ 5] 2.00-3.00 sec 111 MBytes 934 Mbits/sec
[ 5] 3.00-4.00 sec 111 MBytes 935 Mbits/sec
[ 5] 4.00-5.00 sec 111 MBytes 934 Mbits/sec
[ 5] 5.00-6.00 sec 111 MBytes 934 Mbits/sec
[ 5] 6.00-7.00 sec 111 MBytes 935 Mbits/sec
[ 5] 7.00-8.00 sec 111 MBytes 934 Mbits/sec
[ 5] 8.00-9.00 sec 111 MBytes 934 Mbits/sec
[ 5] 9.00-10.00 sec 111 MBytes 934 Mbits/sec
Result when nas is client and nuc8 is server (= very bad):
[ 4] 0.00-1.00 sec 141 KBytes 1.16 Mbits/sec 3 1.41 KBytes
[ 4] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 2 4.24 KBytes
[ 4] 2.00-3.00 sec 0.00 Bytes 0.00 bits/sec 15 4.24 KBytes
[ 4] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 3 1.41 KBytes
[ 4] 4.00-5.00 sec 0.00 Bytes 0.00 bits/sec 3 2.83 KBytes
[ 4] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 2 5.66 KBytes
[ 4] 6.00-7.00 sec 0.00 Bytes 0.00 bits/sec 3 2.83 KBytes
[ 4] 7.00-8.00 sec 0.00 Bytes 0.00 bits/sec 2 4.24 KBytes
[ 4] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 1 1.41 KBytes
[ 4] 9.00-10.00 sec 0.00 Bytes 0.00 bits/sec 0 1.41 KBytes
[ 4] 10.00-11.00 sec 0.00 Bytes 0.00 bits/sec 0 1.41 KBytes
So this is bad! (basically useless, browsing is super slow...).
I already disabled the bios setting and tried to set the ethernet connection to manual but that didn't help...
Please help