Last update (2.1.6) really slowing site down

Hi,
thanks for the great plugin.

I just thought to let you know, my site slowed away down this past few days and I couldn’t find out why, so someone looked at for me. They looked at my metrics and suggested it was this plugin, so reluctantly, I disabled it.
Straight away the problem was cured, and the loading time dropped back to what it normally is, so they were right.

As I say, I’m just letting you know about this.
Thanks.