Red lines for groups due to .vis-group-level-unknown-but-gte1

[ge0ffrey]

I see this bug both in our own project, but also vis-timeline's own example.
See the read borders around "clean house" and "cook":

To reproduce, use this vis fiddle:
https://visjs.github.io/vis-timeline/examples/timeline-generated/jsfiddle.d6d6ca67b2482ff49688e8ce25e2a0a4991ff1bb1c3b91ee036deb30d116d6b5.html

which is featured as the "Nested Groups example" on https://visjs.github.io/vis-timeline/examples/timeline/

[Noxdor]

I am having the same issue.

[heziegl]

to fix this, set treeLevel on groups

// see nestedThreeLevels Example
var groups = [
    {id: 1, content: "Root", nestedGroups: [2], treeLevel: 1}, 
    {id: 2, content: "Child", treeLevel: 2}
];