One website won't load sporadically but ONLY on Windows machine

Hi
We are experiencing a very frustrating problem at work. Suddenly in the last month both our office PCs started having trouble loading our website as well as the Admin/back end of it. However, we DON'T experience this problem with the Apple Laptop! Also, the one PC Laptop, when it is being used at home or other locations to access our website Admin backend it's FINE.

Sometimes it loads fine, then when you try to go into it, it times out and we get the message "The site can't be reached / ERR_CONNECTION_TIMED_OUT" (see below)

We have been working with our Webhosting service, done all the suggestions. We've deleted cookies, flushed DNS, checked speeds, tried different browsers, checked IP addresses... you name it! The problem ONLY happens with our Website and only in our work office and only with the PCs.

Does anyone have any experience with this at all??

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This site can’t be reached

www.suzieblue.ca took too long to respond.

Try:

Checking the connection
Checking the proxy and the firewall
Running Windows Network Diagnostics
ERR_CONNECTION_TIMED_OUT