one Mac downloads; the other doesn't

[GGD]

Mr Downtown wrote:
What should I check on the MBA?

Try creating a new user or using the guest user account on the MBA and see if it works from there. That may tell you if it's an internet connection issue, or some sort of preference / cache issue in your normal user account.

If it works from a different account you might try Chrome's "Clear Browsing Data ..." menu option and clear just "Cached images and files".

Also have you tried a different browser on the MBA, that may also give a clue if it's something with the internet connection or something with the Chrome configuration.