Just purchased an AC1750 Mesh wi-fi extender RE450 to use with an Acer Aspire C24 with a wired (ethernet connection) as have had recent issues with the wifi driver on the computer. 

I have set the extender up and it connects fine wirelessly (checked and my phone works on it etc) however the ethernet connectivity doesn't seem to work! I have connected the computer with the ethernet cable directly to our main router and that works fine but doesnt work as soon as i plug it back into the extender. The computer seems to register that there is an ethernet cable plugged in, but it just says 'no internet' 

Could my computer be blocking it for some reason? I have previously used this method with a different TP link extender and my old work computer that didnt have wifi capabilities and it worked brilliantly so I am baffled as to why this doesnt work! 

I have tried resetting the main router and the extender, I have tried connecting the extender via both the WPS button and also by following the instructions on the Tether app (avoiding using the WPS button) and nothing seems to work.

Any suggestions?!