@SayeemAhmed These are routers with mesh technology like Tp-link routers with easymesh technology and every router has channel selection feature but not mesh systems.

@SayeemAhmed Did u see that there is no channels 149, 153, 157 and 161 which are only allowed in Bangladesh and Pakistan

@SayeemAhmed Yeah i got the update in Pakistan's Google Play Store and i updated to latest version.

@Puneetag39 Try to use AP Mode and then check your speed.

@MarekDDC Update your Deco M4 to firmware 1.7.0 from the link below and then I hope your issue will resolve. https://www.tp-link.com/us/support/download/deco-m4/v2/#Firmware

@David-TP I did every single steps and also changed the DNS and MTU (1492) my ISP is using PPPoE and MTU is (1492) but my Deco is connected to ISP router via ethernet cable and getting dynamic ip...