Getting Half download speed over same setup

[TechLoverboi]

Hi guys.

 

So i got new connection, infact upgraded my older ADSL to VDSL. 

the provider rep came and only like changed router did some settings in the exchange, took 17 days and boom, im on VDSL.

 

now my previous setup was, 

ADSL ROUTER to my TP Link Router in WAN port (blue color ethernet port on router) then one ethernet port from TP link router to my PC. i did that cause my ADSL router had pathetic wifi signals.

 

this VDSL router from provider is good, its signals are ok.

 

but i still connected it to my PC like this

 

VDSL router to TP link router then to my PC

 

but i just noticed today that my TP link router gives me almost half the download speed of internet which is 15Mbps. 

but if i connect the VDSL ISP router directly to my PC thernet port, i get full speed as i have shown in screen shot.

 

the 14ish download is when i connected VDSL router directly to the pc and 7ish ones are when i connect the VDSL to TP Link router then TP Link to my PC. 

 

can someone help? 

[TechLoverboi]

Here is the screenshot i was talking about.