This bug is a part of list found by Russian Wikipedia community in Chart extension after it was enabled on ruwiki for population graphs.

Steps to replicate the issue (include links if applicable):

• Create a page with a chart,
• Edit the page to use another chart. If you try to preview it in 2017 editor, you will see an empty box (though displaying values when hovering).
• If you try to preview it in 2010 editor/save it, it will sometimes look fine. Sometimes it will look extremely narrowed, sometimes blurred (my screenshot from 16 November):

This may also happen when not changing the chart, but when changing the chart parameters (e.g. for Module:Graph:Chart-based ones).

Multiple users on ruwiki on different skins have also reported charts not showing for them until a page reload: This is Andy (Monobook), Футболло (Vector-2010), Shabe (Vector-2022).

Other information (browser name/version, screenshots, etc.):
Google Chrome 142, Windows 11.