Dashboard Graphs Time Series Issues - Stumped

I have a dashboard with multiple graphs which load data from files on startup and then get data from events that happen after that. The file is saved off with a write node after the graph node. They graphs all look perfect when the file loads, but when the new data starts to come in they look like this:

So I have read around and most people seem to have timezone/timestamp issues. I am not sure this is the issue, because if you look at what is happening with the data it isn't a few hours off (I am Eastern, so 4/5 hours off UTC) it is off by days.

I have dumped the data, sorted it, stared at it, etc... and the data doesn't appear to have any issues. They are all unix epoch in ms.

So then I took all the data from the saved file and shifted those epochs to UTC - as a test - and as expected the dashboard converts them to EDT, but the same issue happens.

So then I put in a node which takes all timestamps on new data and shifts them to UTC, nope, same issue.

So them I used that node to make sure the timestamps were in EDT, nope, same issue.

Again is the data were off by 5/4 hours I'd understand this, but they aren't.

I read to try this: process.env.TZ = "America/New_York" ; in my settings.js - doesn't seem to change the outcomes of my tests - either way.

Node-red is running on a RPi v 1.0.2; dashboard node set is up to date.

Any thoughts on why this might be happening? Ideas on other experiments to debug?

You said the graph looks correct after it is initially regenerated so I am not sure what timestamps you have been staring at. If it looks right then I would have thought that they must be right.
Show us what it looks like after the chart has been initially redrawn. Then again after a few new samples have been added.