[Hummingbird] PageSpeed Became Worst After Hummingbird

Hi,
Before I installed Hummingbird Pro version, I was using "Fast Velocity Minify", "Cache Enabler" and "Leverage Browser Caching" plugins. My Google Pagespeed Insights scores for both mobile and desktop were 100/100.

https://developers.google.com/speed/pagespeed/insights/?url=https%3A%2F%2Fwww.47media.com.sg

But after installing Hummingbird and disabling the above mentioned 3 plugins, my scores have worsen to 72/100 and 91/100 for mobile and desk top respectively. Did I do something wrong? Please advice?

Please note my site URL is: https://www.47media.com.sg