Does VM Business Service use Web Proxy Servers ?

I have a 1 Gbps Docsis 3.1 Business Line from VM, which is consistently giving me about 880 Mbps download, and just over 100 Mbps upload, which is fine. In the last couple of weeks, however, I have noticed that Web pages, especially https ones, are intermittently timing out, and you often have to manually retry twice on the Web page to pull it down correctly. If I ping the DNS name of the Website, it is fine, and I think that the network link itself is fine. My impression is that the Web traffic may be going through a Proxy server for caching purposes, and that intermittently, this Proxy service is swamped. Normally, the web reponse is excellent to the same Web pages that have failed before. At the moment, I think that this intermittent behavious is only on https pages, but I am not 100% certain of this yet.

Could some one in Virgin Media tell me whether in fact Web proxy servers are used in a an inital attempt to verify or disprove my theory? BTW, I am an IT Networking consultant, so I thought it best not to go through the standard Help(less) desk, so that I could get a sensible answer to this query !! 😎

Thanks!