httptest ResponseRecorder keeps the old value

I have a handlerAuthentication function that I need to test:

func handlerAuthentication(c *gin.Context) {
	session := Session.GetSession(c)
	var login Login
	err := c.BindJSON(&login)
	if err != nil {
		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	client, err := initClient(c, login)
	fmt.Println("Error: ",err)
	if err != nil {
		fmt.Println("There's an error !")
		c.JSON(http.StatusUnauthorized, gin.H{"error": ErrorWrongLogin})
		return
	}
	err = (*client).Logout(c)
	if err != nil {
		return
	}

	session.Set("username", login.Username)
	session.Set("password", login.Password)
	err = session.Save()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "an error occurred during the save of the session:" + err.Error()})
		return
	}
	c.JSON(http.StatusOK, "Connected")
}

To do so,I made this:

func TestHandlerAuthentication(t *testing.T) {
	UrlOdoo = "https://isi.nc"
	resp := httptest.NewRecorder()
	gin.SetMode(gin.TestMode)
	c, r := gin.CreateTestContext(resp)

	r.POST("/test", func(c *gin.Context) {
		handlerAuthentication(c)
	})

	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	Odoo = OdooRPC{createMockOdooClient}
	client = mock_odoorpc.NewMockOdooClient(ctrl)
	client.EXPECT().Authenticate(gomock.Any(), gomock.Any(), invalidUsername, invalidPassword).AnyTimes().Return(fmt.Errorf("invalid login"))
	client.EXPECT().Authenticate(gomock.Any(), gomock.Any(), validUsername, validPassword).AnyTimes().Return(nil)
	client.EXPECT().Logout(gomock.Any()).AnyTimes().Return(nil)

	session = mock_session.NewMockSession(ctrl)
	Session = SessionGetter{createMockSession}
	session.EXPECT().Set("username", validUsername).AnyTimes().Return()
	session.EXPECT().Set("password", validPassword).AnyTimes().Return()
	session.EXPECT().Save().AnyTimes().Return(nil)

	for name, test := range map[string]struct {
		input   Login
		want    int
	}{
		"valid login": {
			input: Login{
				Username: validUsername,
				Password: validPassword,
			},
			want: 200,
		},
		"invalid login": {
			input: Login{
				Username: invalidUsername,
				Password: invalidPassword,
			},
			want: 401,
		},
	} {
		t.Run(name, func(t *testing.T) {
			body, _ := json.Marshal(test.input)
			c.Request, _ = http.NewRequest(http.MethodPost, "/test", strings.NewReader(string(body)))
			r.ServeHTTP(resp, c.Request)
			assert.Equal(t, test.want, resp.Code)
			resp.Flush()
		})
	}
}

The problem I'm facing is that if I do the tests one by (valid login and invalid login), they all pass, but when I do the two tests at the same time, the second test fails.
Here's an exemple of execution of the two tests at the same time:

=== RUN   TestHandlerAuthentication
=== RUN   TestHandlerAuthentication/valid_login
Error:  <nil> //No error, so resp.Code should be equal to 200
=== RUN   TestHandlerAuthentication/invalid_login
Error:  invalid login //Error, so resp.Code should be equal to 401
There's an error !
main_test.go:394: 
Error Trace:	main_test.go:394
Error:      	Not equal: 
expected: 401
actual  : 200
Test:       	TestHandlerAuthentication/invalid_login
--- FAIL: TestHandlerAuthentication (0.00s)
--- PASS: TestHandlerAuthentication/valid_login (0.00s)
--- FAIL: TestHandlerAuthentication/invalid_login (0.00s)
Expected :401
Actual   :200

As expected, an error occured when the login is invalid, but the resp.Code is still 200.
And if I do the invalid login test first, the resp.Code will still be 401.

Is it happening because the tests are parallelized and the httptest ResponseRecorder doesn't work in parallel ?

Thank you for your help.

Thank you leaf bebop

I needed to initialize a new httptest.ResponseRecorder for each test.
To do so, I move the initialisation to the t.Run(name,func(t *testing.T) function:

func TestHandlerAuthentication(t *testing.T) {
	UrlOdoo = "https://isi.nc"

	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	Odoo = OdooRPC{createMockOdooClient}
	client = mock_odoorpc.NewMockOdooClient(ctrl)
	client.EXPECT().Authenticate(gomock.Any(), gomock.Any(), invalidUsername, invalidPassword).AnyTimes().Return(fmt.Errorf("invalid login"))
	client.EXPECT().Authenticate(gomock.Any(), gomock.Any(), validUsername, validPassword).AnyTimes().Return(nil)
	client.EXPECT().Logout(gomock.Any()).AnyTimes().Return(nil)

	session = mock_session.NewMockSession(ctrl)
	Session = SessionGetter{createMockSession}
	session.EXPECT().Set("username", validUsername).AnyTimes().Return()
	session.EXPECT().Set("password", validPassword).AnyTimes().Return()
	session.EXPECT().Save().AnyTimes().Return(nil)

	for name, test := range map[string]struct {
		input Login
		want  int
	}{
		"valid login": {
			input: Login{
				Username: validUsername,
				Password: validPassword,
			},
			want: 200,
		},
		"invalid login": {
			input: Login{
				Username: invalidUsername,
				Password: invalidPassword,
			},
			want: 401,
		},
	} {
		t.Run(name, func(t *testing.T) {
			resp := httptest.NewRecorder()
			gin.SetMode(gin.TestMode)
			c, r := gin.CreateTestContext(resp)

			r.POST("/test", func(c *gin.Context) {
				handlerAuthentication(c)
			})

			body, _ := json.Marshal(test.input)
			c.Request, _ = http.NewRequest(http.MethodPost, "/test", strings.NewReader(string(body)))
			r.ServeHTTP(resp, c.Request)
			assert.Equal(t, test.want, resp.Code)
		})
	}
}