Wrong URL after calling signIn function when using custom sign-in page

[iltan987]

Environment

"next": "15.1.7",
"next-auth": "^5.0.0-beta.25",
"react": "^19.0.0"

OS: Windows 10 Version 22H2 (OS Build 19045.5487)
Node.js version: v23.6.0
npm version: 11.1.0
Browser: Microsoft Edge Version 133.0.3065.82 (Official build) (64-bit) and Google Chrome

Reproduction URL

https://github.com/iltan987/redirect-issue

Describe the issue

First of all, this example is using custom sign in page.
As I understood, there are 2 ways to redirect user to sign-in page. Server-side and client-side. Using signIn function coming from the NextAuth instance in auth.ts (method 1 in my code) and using signIn function from "next-auth/react" (method 2)
The problem is when you use method 1, URL is not correct but rendered page is correct, just the URL wrong. You can see the correct URL only if you refresh the page manually.
Method 2 works completely fine; both URL seen in browser and rendered page are correct.

How to reproduce

1. Run npm install
2. Run npx auth secret or put your AUTH_SECRET to the .env file
3. Run the app npm run dev
4. In the main page, you will see 2 buttons. Press the one saying "Method 1", you will see wrong URL which includes "/api/auth/signin"
5. Refresh the page (no need to do anything), and you will see the correct URL which is "/login"
6. Go back to main page and press the other button. You will see that you will directly see the correct URL which is "/login"

Expected behavior

Same as method 2, without needing to refresh the page manually, URL in the browser should be same as the URL specified in NextAuth config

[benevbright]

having the exact same issue.

fresh installed few days ago, then facing this issue

"next": "15.1.7",
"next-auth": "^5.0.0-beta.25",

in my old project with the following version, I didn't have this problem

"next": "14.2.0-canary.34",
"next-auth": "^5.0.0-beta.15",

[iltan987]

having the exact same issue.

fresh installed few days ago, then facing this issue

"next": "15.1.7",
"next-auth": "^5.0.0-beta.25",

in my old project with the following version, I didn't have this problem

"next": "14.2.0-canary.34",
"next-auth": "^5.0.0-beta.15",

I tried to see the issue by checking next-auth code. Everything seems fine. I debugged it and URL seems fine. Only thing I suspect is redirect function from next/navigation. It takes the URL. Maybe in that version, there is a bug with redirect function. I don't know. This code piece is responsible of redirecting:

next-auth/packages/next-auth/src/lib/actions.ts

Lines 35 to 39 in af2ccea

	if (!provider) {
	signInURL.searchParams.append("callbackUrl", callbackUrl)
	if (shouldRedirect) redirect(signInURL.toString())
	return signInURL.toString()
	}

I am searching but can someone please check if the issue is because of redirect function in next/navigation?

EDIT:
Updating all packages to their latest available versions including next: 15.1.7 didn't work.
Then, I updated node to version v22.14.0 and pnpm to v10.4.1
Again, didn't work. I didn't get any error, but I got the same result.

[iltan987]

Example app in apps/dev/nextjs is somehow working. I think it's about layout file. Because when I put my code to the root layout file, it starts working... So strange