has someone the same issue with the network card from the NAS , after start out of the standy by it is reduce to 10mbit.
if I reboot my Nas then I have 100mbit
I have this problem since kernel 4.18
thats shows ethtool eth0
4.19.0-0.bpo.4-amd64 #1 SMP Debian 4.19.28-2~bpo9+1 (2019-03-27) x86_64 GNU/Linux