Got upgraded today around 5pm since the last time I checked before the upgrade was around 4pm. Area Lestari Perdana SK.

Router Asus AC66U

Wired to desktop
\

5G wireless to Samseng S8

DWA131?
An USB 2.0 device. USB 2.0 has raw bandwidth of 480Mbps. USB 2.0 has 20% protocol overhead. Effective bandwidth available is 384Mbps. No bottleneck as your DWA131 raw wifi bandwidth is 300Mbps.

Unfortunately....from your wifi analyser screenshot.....you will have hard time getting that effective 60% of 300Mbps bandwidth....
You are sharing your 2.4ghz air time (broadcast time) with 5 different hotspots. Think of it as interference which resulted in non-usable data.

See the edited picture below. The area under the curve is your 180Mbps ( 60% of 300Mbps, remember, wifi protocol overhead ).

I have colored your usable area (bandwidth) in pink color.

If you still remember how to calculate area from secondary school.......then you will know what is your actual effective speed after deducting those overlapping areas.
edit: From rough looking at your wifi analyser result......roughly 50% of your bandwidth is gone from overlapping hotspots from your neighbours.

So....160Mbps divided by another 50% = 80Mbps.........
This is the best case scenario from your screenshot.

Some routers save power by lowering transmit power when not in use. If your neighbour starts to use their 2.4 ghz wifi as well....I imagine the interference will be worse.......

StuartLee2015 just asked the same question for 3 days straight.
No way. ASUS RT-N12HP WAN port is limited to Fast Ethernet 100Mbps. This is your router hardware limitation.

Change your speedtest server.
Webe server is one of the worst server for speed testing.

If possible, test with Telekom Malaysia server, just search for Kuala Lumpur and TM server will pop out.

Read a few pages back...then you will understand why....  
Still no enought what everybody try to advice you yesterday. 

Is that tested via LAN or WiFi?
If LAN could you try with another laptop/pc?

Can you list your hardware NOW.....

I think his signature lists his setup.

When you plugged in cable from your router, disconnect from WiFi before running speedtest. If you don't know how, unplug the WiFi adapter.

He dont have LAN connection...only Wifi 2.4......and questionable 5....
Read yesterday posts...so many people advice him.....

Please use RGX 4400 and stop using asus RT-N12BHP B1........

  Almost there.....

Are you using TM speedtest server?

Saw your edited post

One step you have to do. This is for checking if your BTU port is misconfigured....

If you connect your BTU directly to your Intel 1219-v gigabit LAN, what is the LAN link speed?

Is it 1Gbps?

Sample images;


or

With Cat5 cable your speed is ok,as cable support up to 100Mbps.

Normally, there is a LAN cable connecting from I240G (port 1) to the RGX4400.

Connect that particular LAN cable from I240G (port 1)  to Intel 1219-V.

Question: You sure the LAN cable is CAT5 or CAT5e?

No point. It is just this guy who constantly asking the same questions and insisting that this router supports 300Mbps on 2.4GHz. I am tired of saying the same things repeatedly, so just going to leave it. You can understand how I feel lol.

hahaha...he doesnt understand that theoretical speed are different than real world speed...just let him be...