Over the last 3-4 weeks I’ve seen a dramatic drop in speeds on my Three connection, going from around 120 Mbps down to 5-15 Mbps.
What’s particularly interesting (and concerning) is that if I run the same speed tests via my work VPN (Cloudflare Zero Trust), I immediately get full speeds again (120 Mbps). As soon as I disconnect the VPN, speeds drop straight back to 5-15 Mbps. This is consistent across Speedtest.net, Fast.com and Cloudflare’s own speed test.
This strongly suggests traffic shaping or throttling is being applied to normal traffic, but not to encrypted VPN traffic.
I contacted support and was told that because I’m using a phone SIM in a router (NX500), it’s subject to different traffic/bandwidth management and that I “need a data SIM” instead. However, when I took out the contract I was explicitly advised there was no difference between phone and data SIMs for data usage, and the connection performed perfectly until a few weeks ago.
So nothing has changed on my side:
Same SIM (3Internet APN)
Same router (NX500)
Same location (100m from mast)
Yet performance has dropped significantly unless traffic is hidden behind a VPN.
Can Three please clarify:
What has changed in the last few weeks regarding traffic management?
Whether phone SIMs are now being actively deprioritised when used in routers?
Any transparency would be appreciated, as at the moment the only way to get usable speeds is to tunnel all traffic through a VPN.
