We do have a daily backup that gives some slowdowns at (I think) about 5 AM EST each day (I could be off by an hour or two on that). So if you're primarily getting slowdowns in the early morning, it could just be that. It's been something we've wanted to fix for ages but haven't found a solution yet.
It's also possible the slowdown is somewhere in the pipes between our servers and your ISP. That makes it hard to diagnose. That could be the case even if you aren't seeing slowdowns on other sites. If this is the case, then it's pretty hard for us to directly address.
We're investigating some performance enhancements that
might mitigate both of those issues some eventually, but no guarantees on that.
You reference the central US time zone -- do you live in the US in that time zone, or are you international?
This kind of issue is pretty hard to troubleshoot, especially if it's something only one or two people are encountering.