Web servers seem to go to sleep

I'm having a problem with web servers behind WAF that are not busy seem to go to sleep after a while.

What I mean is, the initial request to one site will take around 14 seconds! if the site has been quiet for a period of time.  It will take around 85ms to respond once it has "woken up".

I have multiple web servers, both Windows IIS and Apache on Linux and they all behaving this way.  I removed them from CDN's to eliminate that.  The only common thread is the Sophos UTM WAF.

I didn't know I had a problem for a few years now because a primary site is very busy and never has an issue.  But this month I built new sites that have low traffic and the results are terrible.  This is particularly bad because Google Bot is reporting errors crawling a new site due to timeouts.

And it's on a dedicated Dell server with 0% average utilization.  I can't find where the hangup is, I've gone through every setting in UTM.