800/85 Speed only last for 6 hours after reboot - goes back to 300/85

800/85 Speed only last for 6 hours after reboot - goes back to 300/85

800/85 Speed only last for 6 hours after reboot - goes back to 300/85
800/85 Speed only last for 6 hours after reboot - goes back to 300/85
2025-09-19 03:54:21 - last edited 2025-10-18 16:25:29
Model: Archer C4000  
Hardware Version: V3
Firmware Version: Latest

Hello, 

 

Original internet plan was 200dl.

Switched plan to 800/50, I'd get around 700/50-800/50 upon router reboot. which is OK if it maintained that speed.

Unfortunately no, it'll drop to 350/50 after 3-6 hours ish.

Upload speed stays high - current plan 800/85.

Same thing, goes back to 350/85 after a bit of time.
 

No devices on priority.

No devices drawing bandwidth.

Currently using Archer C4000

 

Speed test done on tether app - router to nbn. 

 

Any help would be appreciated.  

 

 

 

 

 

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#1
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1 Accepted Solution
Re:800/85 Speed only last for 6 hours after reboot - goes back to 300/85-Solution
2025-09-22 08:20:49 - last edited 2025-10-18 16:25:29

Hello @xO-ArChi-Ox ,

Welcome to our community.

 

Have you been able to reset and configure the router again?

The slow speed that you mentioned is the result of a wireless connection or a wired connection?

Please test the link speed when the internet speed drops:

How to check the associated/link speed on a wireless client.

How to check the associated/link speed on a wired client.

Please connect the PC directly to the modem when the speed drops and test the actual speed from the modem. This is for a comparison.

Nice to Meet You in Our TP-Link Community. Check Out the Latest Posts: △New Firmware Update for Archer BE260/Archer BE400 to Support VPN Merge, New ECO Mode, and More △Connect TP-Link Archer BE550 to Germany's DS-Lite (Dual Stack Lite) Internet via WAN △Tether KidShield Test Recruitment - Safeguarding Children's Online Experience If you found the post or response helpful, please click Helpful. If an answer solves your problem, click "Recommended Solution" so that others can benefit from it.
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#2
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Re:800/85 Speed only last for 6 hours after reboot - goes back to 300/85-Solution
2025-09-22 08:20:49 - last edited 2025-10-18 16:25:29

Hello @xO-ArChi-Ox ,

Welcome to our community.

 

Have you been able to reset and configure the router again?

The slow speed that you mentioned is the result of a wireless connection or a wired connection?

Please test the link speed when the internet speed drops:

How to check the associated/link speed on a wireless client.

How to check the associated/link speed on a wired client.

Please connect the PC directly to the modem when the speed drops and test the actual speed from the modem. This is for a comparison.

Nice to Meet You in Our TP-Link Community. Check Out the Latest Posts: △New Firmware Update for Archer BE260/Archer BE400 to Support VPN Merge, New ECO Mode, and More △Connect TP-Link Archer BE550 to Germany's DS-Lite (Dual Stack Lite) Internet via WAN △Tether KidShield Test Recruitment - Safeguarding Children's Online Experience If you found the post or response helpful, please click Helpful. If an answer solves your problem, click "Recommended Solution" so that others can benefit from it.
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#2
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Re:800/85 Speed only last for 6 hours after reboot - goes back to 300/85
2025-09-23 03:17:52

  @Joseph-TP 

 

Thank you for reply.

 

I've done a reset/power cycle of both the NBN box and C4000 router over the weekend.

Same thing. 

1st test 8:48pm - 796.1/92.7

2nd test 9:20pm - 753.7/91.2

3rd test 1:02am - 390.6/81.7

 

All test done are from the Tether APP - I have no wired computer connected to router - only 1 Tapo Hub connected by wire to router.

Since the speed test is performed on the Tether APP, it should be consistent and would not matter if I did the speed test on wired or not?

Is the Tether App speed test just a direct speed test from NBN Box to Router? 

 

thank you.

 

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#3
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Re:800/85 Speed only last for 6 hours after reboot - goes back to 300/85
2025-09-24 07:50:34

Hello @xO-ArChi-Ox ,

Thanks for getting back to me.

 

It is recommended to use https://www.speedtest.net or the speedtest APP/CLI(https://www.speedtest.net/apps) to test actual speed.

Each time the speed drops, it is best to use a wired PC to test the speed of the modem to rule out the possibility that the speed drop is caused by the modem.

 

Best Regards.

 

Nice to Meet You in Our TP-Link Community. Check Out the Latest Posts: △New Firmware Update for Archer BE260/Archer BE400 to Support VPN Merge, New ECO Mode, and More △Connect TP-Link Archer BE550 to Germany's DS-Lite (Dual Stack Lite) Internet via WAN △Tether KidShield Test Recruitment - Safeguarding Children's Online Experience If you found the post or response helpful, please click Helpful. If an answer solves your problem, click "Recommended Solution" so that others can benefit from it.
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Re:800/85 Speed only last for 6 hours after reboot - goes back to 300/85
2025-10-04 01:46:23

  @Joseph-TP 

Hello, during this last week I got a BE550PRO (used/tested it for 4 hours then returned it) - wifi strength and stability on it was actually considerably worst then the C4000.

Since the c4000 was unplugged for 4 hours and reconnected, speed is holding up.

No idea what has happened but seems to be working now.

 

note: the BE550PRO would have weak/drop out signal strength with speed 75/10 while the c4000 would be strong with speed 400+/80. Same computer on wifi.  

 

Thank you, for your help.

 

 

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#5
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Re:800/85 Speed only last for 6 hours after reboot - goes back to 300/85
2025-10-09 03:16:17

Hi @xO-ArChi-Ox ,

In other words, the Archer C4000 still isn't reaching full speed, right?
But at this point, we still need to rule out unstable network speeds on the front-end modem.
Also, have you tried resetting the Archer C4000? Of course, if the current speed is sufficient for your needs, you can continue with this setting.

Nice to Meet You in Our TP-Link Community. Check Out the Latest Posts: △New Firmware Update for Archer BE260/Archer BE400 to Support VPN Merge, New ECO Mode, and More △Connect TP-Link Archer BE550 to Germany's DS-Lite (Dual Stack Lite) Internet via WAN △Tether KidShield Test Recruitment - Safeguarding Children's Online Experience If you found the post or response helpful, please click Helpful. If an answer solves your problem, click "Recommended Solution" so that others can benefit from it.
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