What might be causing synchronization errors and incomplete application of AI updates?

Computer: Mac 
Version Tahaoe
Lightroom Classic Version:15.5.1

I have recently observed a significant number of synchronisation errors when attempting to share my images with Lightroom (cloud). Many of my images become stuck during the synchronisation process. I have already tried re-builidng sync data to no avail.

Additionally, for images where I have utilised AI enhancements, I need to apply updates. However, when I press Command+Option+U to implement the updates, I receive an error message stating, "Failed to apply adjustments to the following photos.

This is extremely frustrating, as I receive an incomplete copy of my catalogue when I am travelling and using Lightroom Cloud.

Does anyone know what could be cuasing this or what i should look into as a likely suspect?

Thanks in advance.