How to resolve iCloud backup size mismatch after latest iOS Update

I am having exactly the same problem (with no solution) as the OP described in:

iPhone backup issue after 17.4 upgrade - Apple Community

I upgraded my iPhone XS Max from iOS 16 to 17.4.1 and then 17.5 last week. Even upgraded my iPhone XS Max to an iPhone 15 Pro Max with iOS 17.5.1 two days ago using the Quick Start process to transfer all the data. When I do an iCloud backup, it shows that the last backup was successful last night with 2.7 GB size, but the iCloud "Manage Account Storage" doesn't show the iPhone backup (only Docs and Mail that use 1.1 GB size).

I already tried restarting the iPhone, deleting the backup, and creating new backup manually using backup now, etc. The iPhone acts like it is backing up but the iCloud storage doesn't show it. I can still backup to my Mac computer as usual. Interestingly, when I look at my iCloud storage on my Mac (using System Settings), it also shows a 0 KB backup size. But when I click it, the next screen shows a 2.7 GB backup for my 15 Pro Max

Any suggestions on how to fix this? I thought of signing out, restarting, and signing back in but I am afraid that I might lose some data. Everything seems to be working fine.

It has been well over a week and the issues persists with no resolution. I wonder if the iPhone is actually backing up to iCloud and if the backup will be there if I need it.

The account storage may well catch up eventually.

Here’s what’s troubling about your post:

S_Rc wrote:

iPhone backup issue after 17.4 upgrade

After upgrade to latest ios

IOS 17.4 has not been “the latest iOS” since March 21.

Interesting, I recently upgraded my iPhone XS Max from iOS 16.X to 7.4.1 and then 17.5 last week. I have been having exactly the same problem as the OP with the iCloud backup from the upgrades. The iPhone acts like it is backing up but the iCloud storage doesn't show it. However, I can still backup to my Mac as usual. Is this a common problem? How long until it "catches up"?

Here is what finally seemed to work (so far) for me. I completely turned off the iCloud backup from my iPhone and left it off for a few days. (I was a little uncomfortable doing this but I had maintained an iPhone backup on my computer so I had a safety net.). Then when I turned the iCloud backup back and on, everything seemed to work.