Apple appears to have fixed an ongoing iCloud server issue that was causing some apps that have implemented iCloud support to fail to sync properly. The bug has persisted since November, and app developers were becoming increasingly upset with Apple's lack of effort to address the problem.
According to YarnBuddy developer Becky Hansmeyer, Apple said that it has managed to address the issue that was causing sync failures.
Regarding the recent iCloud sync issue, I received a very kind and detailed response from Apple indicating that the underlying issue causing the 503 errors/sync failures has been fixed! 🎉 (Please share!) — Becky Hansmeyer (@bhansmeyer) January 26, 2022
Users of apps with iCloud issues were seeing 503 error messages such as "Request failed with http status code 503," but multiple developers have confirmed that the error messages appear to have gone away over the course of the last couple of days.
Tweetbot developer Paul Haddad said that he has received "basically 0" iCloud Sync reports over the past couple days, and Craig Grannell, who wrote about the iCloud problems, said that he is no longer seeing issues with the Cloud Battery or Transloader apps he uses.
The number of iCloud Sync is broken reports we’ve gotten over the last 2 days has gone down to basically 0. — Paul Haddad (@tapbot_paul) January 26, 2022
I’d be interested to hear whether any devs/users have seen changes in iCloud sync reliability since this story broke. A couple of devs have told me they’ve already seen 503 error numbers dropping. Here, Cloud Battery is now working again, as is Transloader. https://t.co/JM57wqDp70 — Craig Grannell (@CraigGrannell) January 26, 2022
The iCloud syncing bug appears to have been introduced sometime around late November or early December, and it was a major headache for developers. App users experiencing iCloud syncing issues don't know that it's a problem on Apple's end, causing developers to be blamed. Some app developers even went as far as building iCloud status dashboards into their apps so end users would have a better idea of when there were issues with the way iCloud was working.
While most developers have said that the syncing issue has been largely resolved, there are still a few complaints about ongoing problems, so Apple may have a few kinks to work out.
It's worth noting that this iCloud sync issue is an ongoing problem that developers were dealing with for months, and it is separate from the current two-day iCloud outage that is affecting iCloud services.