No longer able to run webpagetest against our site after applying Akamai enhancements

Hi all,

We have applied below Akamai changes to www.beallsflorida.com site:
-Enabled Adaptive Accelration via mPulse lite
-Enabled Resource Optimizer
-Increased Browser cache TTL for js/css to be 10 days
-Enabled Chunked Transfer Encoding
-Enabled Adaptive Image Compression
-Added security headers (Strict-Transport-Security,X-Frame-Options,X-XSS-Protection,X-Content-Type-Options)

After doing so,we are unable to use webpagetest.org to test our site,Webpagetest is returning below error via https://www.webpagetest.org/result/191016_64_9f5ddfc680d404ee5be0c26988ac3c00/ :
The testing completed but failed.
Unhandled exception in test run: Unterminated UTF-8 sequence when encoding string

We are still able to test the site via https://gtmetrix.com and Google .but not WPT.
Can someone help here on what would be the reason ?

Thanks

It might be that the iPhone test agent that you selected was having problems. I was able to run a test using Chrome emulating a Moto G4 - https://www.webpagetest.org/result/191016_TT_4ee8f3d6c8e2e73154cb9bf8c160e1c1/