I can’t say for sure, but sites and services built on the steem blockchain connect to what’s called a “full RPC node” to get and send data to the blockchain. This is a powerful server that contains all of the blockchain data. There are only a very few full RPC nodes available and they have been running into some issues recently as the blockchain grows.

I am guessing that the RPC node that steepshot uses is/was having issues which caused the problems you experienced.

The SteemIt Inc developers have been working very hard on scaling solutions to make it easier to run full nodes and make them run better and faster, so hopefully this will all be a thing of the past soon!