I am seeing this error in terminal "You cannot use different slug names for the same dynamic path" and also localhost:3000 is refusing to connect

Question

I only have one dynamic path in my whole Next.js project, that is, app/api/auth/[...nextauth]/route.js

But for some reason I'm seeing the mentioned error with a elaborated line, that is, You cannot use different slug names for the same dynamic path ('nextAuth' !== 'nextauth')

I can't also see the localhost:3000 and I don't know if those are two different errors or the dynamic path error is causing the latter.

I admit that I'm new to Next.js and I'll be very thankful if anyone can help me out.