Factory reset, new sim, new device or is traffic being "managed"?

[NeedANewName]

At some point between 0600 and 1200 on 2025-12-10 the download speed on my 4G connection tanked and has remained consistently bad since then. The upload hasn't changed but also remains constant. Its a Zyxel NR5103EV2 hub running V1.00(ACIR.1)C0 in IP pass through mode. Its never been run as a normal hub which is why the firmware has never updated.
Its connected to the same cell, on the same mast as its always been and there are no network outages/issues in my area.

Does anyone have any experience of what traffic management looks like on 3s network?

Graphics for info:
10-12-2025 to 12-12-2025

Last 30 days to 23-12-2025 

[NeedANewName]

Or it could just be a network issue (not sure if this is the right info to identify it):

• Tower: 11736
• MCC / MNC / Region: 234 / 20 / 6499
• Bands: 3, 20
• Approximate Address: BA12 0SJ

Connecting via cell ID 3004424 gives a connection speed of 500-900Kbits, that's on frequency band B20. Using frequency band B3 on cell 3004418 gives ~47Mbits.

Not great, but not terrible.

[Paddiewack]

• Three use “traffic sense” as a way of mitigating congestion within the network. It’s usually done out of peak hours as far as I’m aware and only kicks in if the person has used an ( allegedly) inordinate amount of data to the detriment of other users, Sounds fair to me, 

[NeedANewName]

Thanks for the info, that looks a lot like what is happening here, except the mitigation is working 24/7. I have had reason to get a lot of data this year but it should calm down now.

[clivejo]

Looks like the same "issue" as being talked about on ISP Review - https://www.ispreview.co.uk/talk/threads/nasty-new-traffic-management.44236/

[NeedANewName]

Thanks for the heads-up. I'll route everything through a VPN and see what happens. Day before Christmas Eve, what could possibly go wrong?