Starting with your version, SSH is off by default. See here to enable it: emonPi SSH disabled by default
Now the power readings.
Do you have the standard UK single phase supply?
Have you got an a.c. adapter? If so, is that showing a roughly correct value for the voltage in emonCMS. If you haven’t, does emonCMS show a constant 230 V?
Are the c.t’s properly closed around the cables - there’s no dust or dirt on the mating faces of the cores? Are the plugs on the c.t. cables fully home?
Those are the obvious things to check. Beyond that, I can’t say that I can recollect seeing this particular problem before, and I can’t immediately think of anything - assuming you have a “factory” version of emonCMS - that could cause the result you are seeing.