Expected behavior

I expect the datasets/lines to be stacked on initial render.

Current behavior

The dataset/lines will be stacked after an update (i.e. two renders are needed before they become stacked).

Reproducible sample

https://codepen.io/NAndreasson/pen/gONREBm

Optional extra steps/info to reproduce

Click the button in the Codepen to trigger an update

Possible solution

I think the bug is related to the following:

https://github.com/chartjs/Chart.js/blob/master/src/core/core.datasetController.js#L404-L414

In the first render, isStacked will return false which will affect _resyncElements. After updating isStacked will return true and the expected result will render.

Context

No response

chart.js version

v4.4.3

Browser name and version

No response

Link to your project

No response