Good calls!
Service first. Troubleshooting for root cause before implementing change. Rare issues, based on complex config issues are edge cases need time to find (and often not replicable in the lab).
This is first rate engineering.
This Damn War image via Shutterstock Big, global WAN roll-outs have their hazards. Size is one of them, but you can deal with this with effective project planning and management. Complexity is another, but combining design and a team of highly effective and competent engineers can address that one too. And of course there …
Five Guys always reminds me of Michael McIntyre's 'Herb & Spice' skit now though ...