I think that it is not possible to show simultaneously percentage and numeric values in a combined chart (lines and bars). In the attached image, I used a bar chart with numeric values (left axis) and a line chart with percentage values (right axis). As you can see, the metabase does not show the values of the line chart as a percentage although the right axis does.
But besides that, if you click on the issue that I linked long ago, then if the issue is closed, then it's solved and you can see which release it's part of by looking at the Milestone in the sidebar.