This is a weird one, but I am entirely unable to disable Strict Mode in my project. My application needs to create accounts based on OAuth responses from Discord & the creation function is getting called twice which, while the schema prevents the second document from being created, fills the console with errors every time the page loads.

export default async function HomePage() {
    const session = await auth();
    if (!session) {
        return (
            <>
                Click to login
                <div>
                    <form
                        action={async () => {
                            "use server";
                            await signIn("discord", { redirectTo: "/" });
                        }}>
                        <button type="submit">Login with Discord</button>
                    </form>
                </div>
            </>
        );
    } else {
        const discord = session.user!;
        const id = discord!.image!.substring(35, 52); // Hacky method to get ID because Auth.js sucks

        let user = await getOrCreateUserByDiscord(Number.parseInt(id));

        return (
            <>
                <div className="bg-gray-900">
                    Hi <b>{session.user?.name}</b>
                    <br />
                    <br />
                    {user != null
                        ? `Your objectId is ${user._id}`
                        : `no user exists`}
                    <br />
                    <br />
                    Click to logout
                    <div>
                        <form
                            action={async () => {
                                "use server";
                                await signOut();
                            }}>
                            <button type="submit">Log out</button>
                        </form>
                    </div>
                </div>
            </>
        );
    }
}

export async function getOrCreateUserByDiscord(id: Number): Promise<IUser> {
    await database();
    console.log("called"); // Debug line
    return await User.findOne({ discord: id }).then(
        (doc) => doc || User.create({ _id: new Types.ObjectId(), discord: id })
    );
}

import type { NextConfig } from "next";

const nextConfig: NextConfig = {
    reactStrictMode: false,
};

export default nextConfig;

I've tried creating new config files, tried .mjs, .js and .ts config files but none of them fixed it. I also tried entirely recreating my project from scratch with updated dependencies and it didn't fix it either. No matter what I try, it gets called twice, and the called string is logged to console twice.