So you say that you have about 2500+ photos on your iPhone, but only 400+ of them on your Windows PC - iCloud Folder.
This means one or both these things are not happening:
- the photos are not being uploaded from your iPhone to iCloud Server or
- the photos are not being downloaded from iCloud Server to your Windows PC
Let us first check if step 1 is happening: goto a web browser on your PC and goto the website www.icloud.com, Sign-in using your iCloud Apple ID. Then check your photos. Are all your 2500+ photos there?
If yes, then we can go to step 2. If not, then please recheck the settings for iCloud on your iPhone. Do this:
Store your photos and videos in iCloud
Your photos and videos are stored on your device in their original, high-resolution version. This means that they use a lot of space on your iPhone, iPad, and iPod touch. With iCloud Photos, you can make more space available on your device and have your entire collection, everywhere you go.
Get started with iCloud Photos:
- Tap Settings > [your name] > iCloud > Photos.
- Turn on iCloud Photos.
- Select Optimize iPhone Storage to save space on your device.
With Optimize Storage, smaller, space-saving photos and videos are kept on your device while all of your original, full-resolution versions are stored in iCloud. And as long as you have enough space in iCloud, you can store as many photos and videos as you want.