LinkedIn OAuth Error (Help, please!)

I used the same logic for facebook OAuth login for linkedin.

Everything seemed to sit right until, after granting permission on LinkedIn this shows.

Can anyone advice why I am getting this error?
Thanks.

It looks like the return url is set to a defailt value including ‘mywebsite.com

Hi Ben, I edited my URL before i took the screenshot for privacy…
The return URL is my website/api/social/linkedin (The SC function).

DO you have any ideas or suggestions as to how I can mitigate this?