You can see from the following image that my times, when showing on the editing screen, look just fine. Those are the times I went to sleep:

Now, when the times are shown on the graph, they are all out:

Up until today they were only an hour out, now they're two hours. What's going on?
Vivosmart is on the latest firmware, it was connected, checked and charged this weekend. Phone is an Xperia Z3 and is also on the latest firmware with the Garmin Connect App updated to the latest version.
Any ideas? Seems to be an odd bug.
Richard B.