Can't select all album photos for iOS Lock Screen Shuffle

All my photos are on iCloud, and only Optimised Photos are on iPhone. See the Pic Below

Check if any Filters are applied as shown below.

Wallpaper Shuffle selection can go upto 50 Photos as shown in the pic below

Photos that were shared by others can exist in your album but still be ineligible for Lock Screen Photo Shuffle.

Check if some of the Photos are added to the album by others.

1. Open the photo
2. Tap ⋯ → Info
3. If you see things like:
   1. “From Shared Album”
   2. “Saved from Messages”
   3. No camera data (no lens, no ISO, no location)

That photo is very likely to be excluded.

You may try: Duplicating or re-saving them makes them eligible

Hi! It's possible that some of the photos in your album are in a format not supported by the Lock Screen Shuffle, or they might be stored in iCloud and haven't fully downloaded to your device yet. Try going to Settings > Photos and ensure 'Download and Keep Originals' is selected. Also, check if the missing 26 photos are HDR or a different file type. Hope this helps!"