This Article Applied to: 

Archer BE230_V1/V1.20
Archer AX55_V1
Archer AX55 Pro _V1
Archer AX72_V1
Archer AX72 Pro_V1

Phenomenon: 

Some users have reported performance degradation in their routers after enabling QoS following a firmware update.

Specifically, Bufferbloat test scores for both wireless and wired clients have significantly decreased (e.g., from A/B to F). Serbian_Fantom mentioned this unexpected behavior here.
Additionally, a noticeable increase in upload latency may occur, resulting in higher latency and jitter when the network is under heavy load.
Disabling QoS can resolve the performance degradation described above.
We have identified the cause of these unexpected behaviors. Please take a look at the following feasible solutions.

Available Solutions: 

Solution 1:

Our development team has provided the following beta firmware to address this unexpected behavior for the models that have already been reported. Please install the beta firmware for your router if you encounter this anomaly.

Note: 

• Please be sure you have read the Beta Test Agreement before upgrading the beta firmware!
• For the sake of insurance, it's always recommended to save a copy of the router's Backup Config file before upgrading or downgrading.
• You may follow the guide to upgrade the firmware of your router. How to Upgrade the Firmware on the TP-Link Wi-Fi Routers.

Solution 2:

If you don't want to try the beta firmware, you can temporarily disable the QoS feature.

We welcome you to share your experiences with the beta firmware. If the beta firmware doesn't help, please provide details on your router's current operation and any other relevant information. Like the complete network topology, specific exception details, when the problem started, etc.

What if your router model isn't among those mentioned above, but you've also experienced unexpected bufferbloat and high latency after enabling the QoS feature during firmware updates?  Please provide your router model, including firmware and hardware versions, for reference: How to find the hardware and firmware version of my TP-Link device?

Thank you for your feedback and support.