No no, I am only using 30Mbps plan but I am not referring to ISP. I am doing WiFi Transfer within my own network and the ISP internet speed should not be in the Picture.

Tried setting the bandwidth to 20/40/80MHz, didnt help much in my case.

You're welcome. if you want a peace of mind just go for the flagship smartphones, you'll get the latest and greatest 2x2 MU-MIMO chip, it can't be wrong.

Something I'd like to point out though it's a shame that in year 2019 those smartphone vendors still didn't put 802.11ax chip into their flagship smartphones like the Huawei P30 series, Xiaomi Mi 9, Redmi K20 Pro, LG G8. So far only Samsung did it with their Samsung Galaxy S10 series. Then there's another smartphone vendor OnePlus famously known for their "flagship killer" slogan with flagship specs at an affordable price? Release their OnePlus 7 Pro in May 2019 after Samsung Galaxy S10 in February 2019 but still failed to put a 802.11ax chip into their smartphone. Yeah right "flagship killer" , maybe need to wait year 2020.

Added more information into my previous post.

People say TM router is crap but I have a different experience.

I have 800Mpbs but could never get that with AC1200 supplied by TM, around 400Mpbs. So I went out to get a Asus AC68 and CAT6 cable to hook up to my desktop computer. I still get the same 400Mbps on my desktop

I complained to TM and their technician came. They took out their beat up TM router and getting 600 to 700 Mpbs instead. So I can't complain any more.

Then one day, my AC68 refuses to connect for whatever reason so I took out the TM AC1200 again and hook up. Sure enough, I am getting the same speed of 400 Mpbs of my Asus AC68

BTW, I didn't do any special setting. I just hook up, log into my account and use both routers. May be I need to do some special setting on my Asus that I didn't know about.