I am new to MikroTik, just received my CRS125-24G-1S but have a lot of professional experience in the network world.
The CRS was simple to configure and has been performing above expectations. I currently have a very simple configuration:
Port 1 - WAN
Port 2-24 - Switch (default configuration)
DHCP/DNS configured for clients.
I woke up today to a network performance issue that was causing all clients and internet access to slow down to a snails pace. After a couple hours of troubleshooting I figured out that the cause was an Intel NUC (DCCP847DYE) that was powered off.
The link for the NUC was showing 10Mbps Full while powered off. If I power the device on or unplug it completely the performance anomaly goes away.
Not sure if anyone has experienced this or can offer in advice on how I might go about solving this issue. 
Thanks in advance.