from the user's computer hardware, OS and network, to the internet connection of the user, to the ISP's connection to the Internet backbone, to the routing scheme of the backbone, to the web hosting company's connection to the Internet backbone, to the corporate network of the web hosting, to the hardware, OS of the web server,to the system software of the server, to the web site server software. If anyone of these factors has an issue, the whole process would not be satisfying.


Since the issue appeared to be limited to individual users, it's more likely that the problem was related to the users' ISP. The website operator basically is not able to do anything in such situation.

What the website operator can do is to ensure that the part within their capacity works properly.