API Version 1 appears to be throwing up an error. V4 works fine.
I’m not sure if I want to get into explaining how to correct the issue nor am I sure if it’s my place to do so.
Out of pure curiosity, why did you go with the google api for small screenshots and the wordpress mshot for the larger? I genuinely don’t know so just trying to understand the reasoning behind it so I can better edumacate myself.