The changelog

Summary: This is the page to check for details on what has changed. The changes may or may not be relevant to you.

June 2020 (v5.24)

The SVG Line chart now supports three new properties: dashed dotted and dasharray. This allows you to specify your line(s) to be dotted, dashed and also give your own style of linedash. The dasharray should be an array of two numbers - the length of the dash and the length of the gap.
The charts that have a Y axis (ie the Bar, Gantt, Horizontal Bar, Line, Scatter, Waterfall charts and the drawing API Y axis) before now rendered their Y axis title in native canvas text. This was because vertical accessible text had positioning and alignment issues. Now that these have been resolved (in a previous release) these charts have been updated to use DOM text to render their Y axis titles.
In what was most likely a regression - the default for the Bar chart labelsAboveOffsetx property has now been set to zero.

There are notifications and advisories regarding backwards compatibility that you can read here: https://www.rgraph.net/canvas/docs/backwards-compatibility.html

Older release notes though are not available.