Of the 4 keys, 3 of them contain no more than 30 KB of data each. However, one of the keys can contain as much as 160 KB of data which will not sync to another device. Strangely, if I constrain the data to 100 KB it will work, however, that is not ideal as it is a fraction of the necessary data. For the purpose of clarity, the above should read: Of the 4 keys, 3 of them contain values which are no more than 30 KB of data each. These 3 key-values will always perform a successful sync. However, the fourth key contains a value which can be as much as 160 KB of data and will not sync to another device. Strangely, if I constrain the data to 100 KB it will work, however, that is not ideal as it is a fraction of the necessary data.

It appears that this issue was resolved in Xcode 16.2 (16C5032a)

I can confirm that this issue has not been resolved in Xcode 16.1 and continues to make development frustrating. DTS Engineer, can you help prioritize this issue to be fixed by the Xcode team?

I'm seeing the same thing and filed FB15150709 - Xcode 16.0 (16A242d) Developer Documentation is not showing Objective-C APIs.