Facing huge network latency (upwards of 3000 ms) & packet loss (request time outs) when on online meetings OR online classes. Would appreciate if any help is available.

See the attached pic.

I have very basic use case & setup:

1. Online meetings/classes using Google Meet / Microsoft Teams on "Windows 10" laptop / Android table. Bandwidth need for these is not much.

2. Max 3 such simultaneously connected devices. All devices are in close vicinity of router & getting good signal strength.

3. Internet connection type: Fiber & bandwidth ~100 mbps.

Observations:

1. Above setup works perfectly fine on my mobile phone hotspot which has much lesser bandwidth than my FTH internet connection.

2. Wired connection to router works perfectly fine. I have tested with 2 laptops on LAN (max supported) and one on WiFi & in this case laptops on LAN works fine, whereas the one on WiFi faced ping spike + disconnections.

Troubleshooting tried so far:

1) Firmware Updated

2) Multiple Channels are tried, including the channel on which my mobile hotspot works.

4) Global DNS setup

5) Hard reset and Reconfiguration

6) MTU Size has been altered

7) Lastly we even replaced the router from TPlink Service Center & repeated the above steps with the replaced router as well but the problem seems to have worsened now with refurbished/replacement router. Pings during normal browsing are also unstable now, going till 200 ms.

TP link India support folks are ignoring my mails, overall really bad experience. Not sure why TP-Link is not able to solve this basic use-case.