A Microsoft file hosting and synchronization service.
Hello,
Just to clear things up right away since you asked Microsoft to check this out, this is a public forum staffed by users just like you, not Microsoft employees. We cannot poke around their servers or redeploy files to the CDN.
Your devtools trace is spot on and proves the issue is completely on their end. Since you are seeing a literal 404 from the Akamai edge on that react script even when bypassing your iframe, there is zero you can do to fix this locally. You are just going to have to wait for the server side fix like the last time this happened.
The fastest way to get their engineers to notice the missing file is to send those exact headers and network logs through the feedback option inside the OneDrive web portal or open a support ticket in your Microsoft 365 Admin Center if this is a business tenant.