Not sure this is a Webpagetest bug, but as the website is loading well within 2-3 seconds, I presume so.
I tweaked a Wordpress website to load within 2.3 seconds, improving load speed from the former 5 seconds. Webpagetest.org server is at Los Angeles and website server is at Los Angeles.
With everything running fine, as a last tweak, I enabled HTTP/2 on the LAMP (Apache 2.4, PHP 7.0) server.
On enabling HTTP/2, the Webpagetest.org will tell me that Time to First Byte is now F (from A), and all the website images and webfonts result in 404. Website load is over 19 seconds. I disable HTTP/2 and Webpagetest.org will work properly. See screenshot here https://www.diigo.com/item/image/5pj5q/y75a
I could not find any information about issues between HTTP/2 and .png/.jpeg images. Is this an issue with Webpagetest.org?
Any advice is welcome.