@Joseph-TP Yesterday, I upgrade firmware to latest version again. Now it seem back to normal speed. Thank you for your support.

@Joseph-TP 1. Speed test results when the issue occurred: When connected via Wi-Fi, the speed dropped to around 200 Mbps (download/upload) When connected via LAN, the speed was normal at 2000 Mbps,...

I use TP-Link BE800 Router, After the upgrade to latest firmware, I noticed a significant speed drop over Wi-Fi all the band (5GHz, 6GHz, and MLO.), while the LAN connection remains normal. I tested...