@Shishi22 These are not very informative. Post WAN and LAN settings from HUAWEI router: Post the basic WLAN settings (not advanced): If the RE215 is currently running as a range extender post its...

@Shishi22 In this case if you want to troubleshoot the issue, you should post here some screenshots of your ISP modem model, its Wi-Fi, WAN/LAN settings, as well as the RE215 LAN settings Without...

@Shishi22 Reset the RE215 to its factory defaults by press and hold the reset button for about 10 seconds. Once reset use this video guide to connect RE215 to your ISP modem. Using an ethernet cable...

@Hizzzon AX12 is a dual band wireless router: IEEE 802.11ax/ac/n/a 5 GHz IEEE 802.11n/b/g 2.4 GHz It can provide dual band wireless connectivity in both wireless router mode and access point mode.

@TheFriendly Test the speed from a wired device and make sure that QoS feature is disabled:

@Rich---- I understand your point regarding different proprietary mesh technologies. Many network equipment manufacturers have developed their proprietary mesh technology as well. AFAIK what TP-Link...