If I am understanding it correctly then you are facing slowness issue and it is not permanent.
Tuning the WLAN and AP settings may be required.
Few common things you can try are:
- Use only 5G radio and disable 2.4G radio.
- Or create a dedicated SSID on 5G radio and test with it.
- If you have more then 1 AP, please change the BSS minrate to 12 Mbps.
- Test the speed using any online internet speed testing tool.
- When you face the issue, start ping from problematic device to gateway IP (I am not sure if that can be done using Xbox or not but for most of the laptops and mobiles device you can do it).
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