This issue is caused by WebKit bug (#23113), which affects how foreignObject elements render scrollable HTML content inside SVGs on Safari.

In this case, JointJS uses foreignObject to embed HTML within SVG elements. Safari sometimes renders the inner content incorrectly—typically pushing it to the top-left of the canvas - especially when overflow-y: auto or scroll is applied.

This isn’t a bug in your code or in JointJS - it’s a Safari rendering limitation that has persisted for years. Until Apple updates WebKit’s support for foreignObject, these issues will continue.