Re: Several photos missing from my device : Is there any way I could restore my photos?
Check if the photos are available in Photos > Albums, then tap Recently Deleted in the Utilities section.
If the photos are there, you can likely restore them.
See: If you're missing photos or videos in the Photos app - Apple Support
Eg: says:
- In iOS 16, or later, use Face ID or Touch ID to unlock your Recently Deleted album.
- Tap a photo or video, then tap Recover. To recover multiple photos, tap Select, select your photos or videos, then tap Recover.
- Confirm that you want to recover the photos or videos.
_________________________________________________
Re: I have plenty of space (175gb available) in my iCloud
iCloud. is mainly a sync service,(apart from back-ups) & generally only stores files that are actually on your device
See: What's the difference between device storage and iCloud storage? - Apple Support
You may want to check if your device itself is short on storage:
Eg an iPhone will generally need to keep around 8 Gb free in order to operate smoothly, and do what you ask it to.
How to check the storage on your iPhone and iPad - Apple Support
If your iPhone is short on space, it is wise to back-up everything on your iPhone.
and
If needed: Scroll to: "Manage space on your iPhone, iPad or iPod touch" in the linked article below:
To make space on your device, try the recommendations.
If you need more space for an update on your iPhone, iPad or iPod touch - Apple Support