[Smush Pro] Divi logo failing to load when using Smush CDN

The logos on several of my sites are failing to load.
On hunch I disabled the CDN function of the Smush plugin on one of my sites and this fixed the problem.
The site is built using Divi. I'm not sure if this is a Divi issue, or a Smush issue.
Is this a known issue? Is there anything I can do about it? I'd like to continue using smush CDN.
Thanks for your input. - Tom