The Asus looks to have LAN port 4 set to WAN - this should be off

For the Asus - ensure Dual WAN mode is off and set WAN Transfer Mode is not enabled

For reference anything with Router Mode in the name isnt Bridge Mode.

What port is the Asus connected with?

I'll go give that a go now.

The asus is connected to port 2 on the tp link from its own port 4.

There's the issue - Port 4 on the Asus was set as WAN

Alright, so this as all working, but i'm back to my original issue. Slower speeds using the Asus. So darn wierd.

Asus speed test https://www.thinkbroadband.com/speedtest/15499989964...

Tp link speed test https://www.thinkbroadband.com/speedtest/15499990797...

I'm stumped. Perhaps i should just switch the Asus and Tp link around as i don't have this issue when doing that. WIFI performance will suffer but not sure what the problem can be.

Ethernet results to rule out WIFI

Directly from tp link to laptop https://www.thinkbroadband.com/speedtest/15499995132...

Directly from Asus
https://www.thinkbroadband.com/speedtest/15499995973...

OK, on the Asus have a look at the Traffic Manager Tab

Sorry should have said

Check if Bandwidth Limiter is off

Then on Traffic Manager Tab, you should be able to see the throughput when you run your speedtests.

Is there anything else connected to the other Asus ports?

Also check in the TPLink under Bandwidth Control for any rules

It sounds like the TP Link to Asus has dropped to Half Duplex - easy way to test that would be to relocate the Asus to the TP Link location and use a fresh network cable... in that test a wired connection to the Asus should be the same as a wired connection to the TPLink

Sorry for the delayed responses. Can't even access the Asus page now. On any device.

Tried Router.asus.com and 192.168.1.1 (Kept it at that after a router reset)
Tp link is now 192.168.2.1

Not sure why i can't connect to router page now. Restarted it with no luck. Can still connect to the internet and all that. Tried removing ethernet that was connecting the 2 routers but that hasn't worked either.

Yes, my ps4 and smart tv are connected to Asus device. Sometimes my laptop too. All showing similar speed results. Give or take a few meg