Time To First Byte 3 Seconds – Site Loads after that in 1-2

Hello all, I am wondering why in the world the first byte time is so slow.
It didn’t used to be until recently.
Our set up is opcache and redis.
Redis works really well with the theme and sped it up tremendously.
I have gone through all of our 46 plugins and there has been no change, i personally don’t believe it is the theme, which testing confirmed.
We are using inmotion hosting and on a dedicated server – we do have a high traffic site.
Here are some examples: https://www.webpagetest.org/result/161211_1P_5GK/
Pingdom: https://tools.pingdom.com/#!/dZoNss/https://christiantruther.com
GTmetrix: https://gtmetrix.com/reports/christiantruther.com/0lcfGHPR

Any help would be greatly appreciated.
Nate

Hey Alin,
No worries – I just wanted to see if anyone could help because my hosting company doesn’t seem to be able too. All is good though – we fixed it, I think.
The set up is opcache, redis, and super cache – site loads in 1.2 seconds on average..