Unable to expand multiple downstream pipelines.

Summary

With multiple downstream (downstream trigger to another downstream trigger), the UI will not properly expand any subsequent downstream pipeline.

Reproduced on 12.5, Gitlab.com, and 11.10.7

Steps to reproduce

Create three projects, one project to trigger second, which triggers the third.

# First
trigger:
  trigger: davinwalker/downstream-second

# Second
trigger:
  trigger: davinwalker/downstream-third

# Third
build:
  script: echo 'do work'

Example Project

Example pipeline reproducing the issue (gitlab.com) https://gitlab.com/davinwalker/downstream-start/pipelines/104175273

3 Projects, the first project triggers the second, the second has a job which triggers the third. When attempting to expand the third pipeline the UI will reset.

What is the current bug behavior?

UI Collapses rather than expanding/showing downstream and upstream pipeline

What is the expected correct behavior?

Display downstream and upstream pipelines

Relevant logs and/or screenshots

No errors in the console logs.

Relevant links

Looks like we've had regressions on this before.

#8688 (closed) #9826 (closed)

MR for added feature

Internal ZD

Possible fixes

(If you can, link to the line of code that might be responsible for the problem)