用户 findOne 返回 nil，但数据存在于 Go Fiber Go Mongo 中

err := usercollection.findone(ctx, bson.m{"email": input.email}).decode(&input)

func SignInUser(c *fiber.Ctx) error {
    ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
    var input models.User
    defer cancel()

    if err := c.BodyParser(&input); err != nil {
        return c.Status(http.StatusBadRequest).JSON(responses.UserResponse{Status: http.StatusBadRequest, Message: "error", Data: &fiber.Map{"data": err.Error()}})
    }

    input.Email = util.NormalizeEmail(input.Email)
    fmt.Println("received data", input.Email)
    err := userCollection.FindOne(ctx, bson.M{"email": input.Email}).Decode(&input)

    if err == mongo.ErrNoDocuments {
        fmt.Println("User not found>>>")
    } else if err == nil {
        fmt.Println("err")
    }
    return c.Status(http.StatusNotFound).JSON(responses.UserResponse{
        Status:  http.StatusNotFound,
        Message: "Account not found",
        Data: &fiber.Map{
            "data": "No Account belongs to given credentials"}})
}

return c.JSON(fiber.Map{"status": "success", "message": "User found", "data": input})