Today, all node combination I tried are all bad. Ping very unstable, go between 2xx to 5xxms. While in the suggestion, all show up as around 200ms. I’m better off not using mdufish today. What’s wrong with mudfish today?
Frankly speaking I don’t know. 
However did you try to use ‘basic mode’ first rather than ‘advanced mode’ for node pickup?
If you still see these symptoms even with ‘basic mode’, please check ‘Status -> Nodes’ menu to check RTT stddev values to mudfish nodes.
- Please leave what you want to play alone then close other programs.
- Picking a node that shows near flat graph may considered more consistency.
- In general, network congestion has getting increased on night to early morning.
How to pick the best mudfish node for game I play?
- You can inspect how network traffic goes on with tools like WinMTR or PingPlotter.