Since we can't see your setup, perhaps you could include more information
- What iOS are you using on your iPhone?
- How are you trying to transfer these pictures?
- …Are you using a cable or WiFi?
- …with Finder? or
- …with Image Capture
- …or with what app?
- Or are you using iCloud Photos to synchronize your devices? If so
- …Do you have “Optimize Storage” checked in Photos’ Settings on the phone or the Mac?
- …Do you see all your iPhone pictures at iCloud.com?
- …Do you see all your Mac pictures at iCloud.com?
- …Have you checked to see if the Apple Account is really really the same on the Mac and on the iPhone and at iCloud.com?
- …Do you have more than 10% free storage on your iCloud account?
- Where does your Mac's Photos Library reside-- in the Pictures folder of your internal drive, or on an external drive? or on a network? on iCloud drive?
- What is your storage on this iPhone? At Settings>General>iPhone Storage, my phone says 50.5 GB of 128 GB used. What does yours say? Do you have more than 10% free storage on your iPhone?
- What is your storage on this Mac? At System Settings>General>iStorage, what does yours say? Do you have more than 10% free storage on your Mac?
- Do you have more than 10% free storage on your Mac?
- Were all 4000 pictures taken on you your iPhone 16? or were they transferred?
What have you tried?
- re-started your Mac?
- Forced restarted your iPhone?
Force restart iPhone - Apple Support
This is different from a simple Power Off. I had to continue holding the button down past the "slide to power off" message, and then I released the button only after the Apple Logo appeared indicating a re-start.
- re-started your Mac in Safe Mode?
Start up your Mac in safe mode - Apple Support
