I logged into your website and see you have an old version of Integral Pro, version 1.2.6 which is 3 years old.
Also, you have many plugins enabled.
I would start by disabling plugins until the problem disappears. Then you will have identified the problematic plugin.
Also, I would suggest you update to the latest version of Integral Pro.
You can log into your account and download the latest version.
If you have any issues, please let me know.