RB951G 2HnD link up/down on ethernet port

I have an issue on my RB951G 2HnD, router OS 6.10 now.
I had the same issue on 6.7 and earlier versions.
The issue is link up/down on every ethernet slave port((( Ethernet slave 3 is a Samsung TV ue37C5000… it suddenly shuts down (stops playing movie from my HomeMediaServer on a PC via dlna)
Don’t know what to do(((
If somebody have a decision plz kindly tell me what to do!!!
Thanks
Безымянный.jpg