This has been on the back-burner since 2016. It could still burst to produce real problems for South Sudan, Ethiopia and Kenya.
South Sudan and Kenya have met to try to resolve the issue, but since 2016 South Sudan’s internal difficulties appear to have slowed progress as regards demarcation of a border with Kenya.
“Perhaps the Ilemi border issue will at last be settled by the two governments principally concerned. Time will tell.”
This is a good background paper: Ilemi Triangle – A Border Too Far