Console in very slow winbox and ssh

Hello,
I am facing a difficulty when executing commands using SSH with DSA key.
I have a system that does client execution and control for providers, and some servers have crashes. When I open the terminal in the winbox it does not open to enter commands, and in ssh it authenticates and gets locked as if it were executing the command.
Can someone give me a hint of how I find out why?
Usually every 2 days these servers cause this problem. Today they were stuck from 1 o’clock to 8 o’clock when they asked to restart.

Sorry my English, using google translate.