Hello!
Thanks for getting in touch with us. My name is Muhammad.
I see the websites are slow. The main reason for all your domains is the initial server response is taking the time.
I logged in to all the domains and I do not see any cache plugin used to speed up the site.
Please check our doc here which will surely help you improve the speed of the site and please contact your host and ask them to enable the CDN on the site. CDN is the content delivery network that controls the rendering of your resources efficiently and intelligently.
