To resolve multiple downloading and updating issues, go to System Settings, click on Wi-Fi, click on 'Details' on your current connection, turn off the option 'Low Data Mode', then click 'OK'. You will then need to type your Password or use Touch-ID. When done, you can then download/update easier.
This worked for me to download relevant Apple Intelligence files on MacOS Golden Gate as earlier on Tahoe I had difficulty downloading the files needed to use Image Playground after updating my Macbook Air 2020, M1 Chip to Tahoe 26.5.
[Edited by Moderator]