Hello Actressgal,
This page can help out with issues within iCloud Photos: Get help with iCloud Photos - Apple Support
The steps here can help to see if there may be a sync in progress: How do I check the status of my uploads or downloads to iCloud Photos?
1. Open the Photos app.
2. Select the Library tab, then tap All Photos.
3. Scroll to the bottom to see the status bar.

Also check to see if there's a Smart Album named "Unable to Upload", which can be created if there are one or more items that cannot upload at the moment. If that's the case, try editing the items within and see if that's helped.
Also check for any available iOS/iPadOS updates on each device to ensure they have the latest improvements/fixes: Update your iPhone or iPad - Apple Support
Cheers.