So yeah, #1 is just a bug.
The two timestamps are because the X axis is at a different scale at the time you’re looking at it than the navigator axis. The navigator (should) always show the full range of the trend you’ve configured: it looks like a year in this case? The X axis above it shows the range for the currently selected bit of data: about an hour and a half.
Changing the selection in the navigator will change the values shown on the X axis.
As for why no data is showing: very long range trends are buggier than I’d like, and it’s very hard to zoom in enough to show live data on them.