@y-nishihara 

Hi, thanks for posting question here. 

You can find router model on its bottom label.

May I confirm all your wireless devices are arduino's (arduino Nano33 Iot) ? Or you have other wireless devices that are wirelessly conected to router stabily?

If  only your arduino's devices are experiencing frequent dropouts or losing internet connectivity when connected to a TP-Link router, there are several potential reasons and troubleshooting steps you can take:

    1. Check Wi-Fi signal strength: Ensure that the affected client devices are within range of the TP-Link router and not obstructed by obstacles. Consider repositioning the router or using Wi-Fi range extenders to improve coverage.

    2. Adjust wireless channel: Change the wireless channel on the router to minimize interference from neighboring networks.

    3. Update client device drivers: Make sure the network adapter drivers on the affected client devices are up to date.

    4. Disable router features: Temporarily disable advanced router features like Quality of Service (QoS) that may be causing compatibility issues with specific client devices.

    5. Update router firmware: Check for and install any available firmware updates for the TP-Link router to address compatibility issues and improve stability.