I'm not sure EON.Next app or systems support legacy data, but if you have been migrated from another supplier then chances are the system works differently from what you are used to.
I don't trust anything in 'the cloud' or any data that can be lost or not transferred when systems or suppliers change, so I just track all my data on an off-line spreadsheet, and have done since 2006. Your data is only your data when you can store it locally, is my motto.
I appreciate that may not be much help to you retrospectively, but I've been bitten too many times by new technology to ever not store and monitor my own information.
Not only that, but with your own spreadsheet you can extract much more information if you need to. I use mine to compare current and previous properties to be better informed as to what energy efficiency measures make more of an impact in different situations.