Archer NX600 v2 – Significant speed degradation until mobile data reconnect (Vodafone Germany)

Hello everyone,

I received my new Archer NX600 v2 yesterday and have been testing it on Vodafone Germany. I've noticed a strange behavior and would like to know if other users are experiencing the same issue.

Issue

The router can initially achieve excellent speeds (250–550 Mbps download, which only became possible after installing the latest firmware). However, after some time, the speed drops significantly, sometimes to around 40–50 Mbps, while remaining connected to the same tower and bands.

The interesting part is that simply disconnecting and reconnecting the mobile data session immediately restores the higher speeds without requiring a router reboot. This happens regardless of which Vodafone APN profile is selected.

Setup

• Router: Archer NX600 v2

• Firmware: 1.3.0 3.0.0 v60ec.0 Build 260311 RC.54933n

• ISP Version: 25111103

• Network: Vodafone Germany

• Mode: 5G NSA (N78 + LTE anchor B1/B7/B20)

• Same SIM card

• Same physical location

• Same antenna position

• Same tower / Cell ID

Comparison with Archer NX200

I also own an Archer NX200 and can perform a direct comparison under identical conditions:

• Same Vodafone SIM card

• Same location

• Same antenna position

• Same tower / Cell ID

• Same time of day

• Same ISP Version (25111103)

The NX200 is noticeably more stable and does not exhibit these large speed fluctuations. While its peak speed is generally lower than the NX600, it maintains much more consistent throughput over time.

Observations

• Tower remains the same

• N78 remains active

• Signal levels remain relatively similar

• No router reboot required

• Reconnecting mobile data restores full speed instantly

• The issue occurs repeatedly

Example

• After reconnect: ~250–550 Mbps

• Later: ~40–50 Mbps 10 minutes or so 

• After another reconnect: back to ~250–550 Mbps

I have already updated to the latest firmware, but the behavior still occurs.

Additionally, a friend of mine owns another NX600 and is experiencing very similar symptoms, which makes me wonder whether this could be firmware-related or modem-related rather than a hardware fault.

Has anyone seen similar behavior on the NX600, especially on Vodafone Germany or with the Quectel RG500Q modem? Are there any recommended settings or workarounds?

Thanks.