TM replaced my old router with DIR 850L, now the connection much unstable. Only 30% speed on different floor. Any good/long range router for replacement?

lol, that i have to go outside my house and even out of my house gate to peek into a small window and find out

psst, double storey semi D, i not a flat or condo

YouTube crawling at the moment....

YouTube crawling at the moment....

Youtube and other streaming very slow now. And TM speedtest sometimes fail and sometimes get only around 10-20 on 50mbps connection. Very frustrated ;(

anyone experienced noisy phone line for unifi voip phone before?

symptoms: caller of incoming call to my unifi voip cannot hear anything from my side. whereas i can hear them over the phone. also, can hear static noise when i pick up the phone (during dial tone).

wondering how unifi, using digital signals can have static noise, unless something wrong with BTU 

i tried rebooting power for both BTU and router then line will be back to normal. so far happened to me twice. still the same after trying with two different TM supplied cordless phone. using alcatel BTU and tplink c5 on Adv50 FTTH.