Stuttering while playing UHD

on previos version i can play UHD video with very high bitrate trough network.
With last version, kodi goes stuttering with a normal bitrate (35v+5a Mb/s).
Adapter works like a gigabit adapter:
ethtool usbnet0
Settings for usbnet0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised pause frame use: Symmetric
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Link partner advertised pause frame use: No
Link partner advertised auto-negotiation: Yes
Link partner advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Port: MII
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: pg
Wake-on: g
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes

I’m using advancedsettings.xml (as usual)


I can see the movie only with initial pause, buffer goes to 100%, then while playing it stay about 50% (+/- 10%).
Why this problem?
Thanks in advance

ps: 905X + 2gb ram + usb3 (but with usb2 port) gigabit adapter

Have you tried to play the UHD content without the Gbit adapter, using your box’s 100 Mbit port? Do you see any stuttering then?

Here is a thread for Working USB Wifi/Ethernet adapters for CoreELEC which could be helpful. Try to run som iperf3 tests with different settings to measure bandwidth, packet loss, delay jitter etc which could give us some insight why the content you want to play is buffering.