I changed the x-trace date format to include seconds. Not ideal, but it kind of works.
Sometimes you really need to zoom in so the xtrace isn't on top of each other.
If you have the combination: powerchart + historical deadband + a dodgy connection, be aware!
I have a lot of 4G cellular connections, so a loss of communication is common for me.
Had a lengthy chat with support about this and the conclusion was that this is the intended function.
There was some talk about a future request, but i havent heard anything yet.
Only way to "fix" this is to have a really small maximum time between samples. The problem isnt fixed either, its just limited to the maximum time.
A picure says more than a 1000 words 
If data integrity is 0, then powerchart uses the timestamp, but the not the value of that entry, to create a flat line on the chart.
This is how the database for this trend would look like:
In my opinion the line should have been drawn up to the point of loss of communication.
The data (value 3 in this case) is even in the database!
Guess they deem the information to be inaccurate.
But they still use the timestamp to draw a flat line, its weird.
Stopping the line at the last entry of dataintegrity 192 would also be better, but not ideal.