Netlify Deploying React JS app but I can' get any page after signin

This is my first question

I created an app in React JS and Ruby on Rails. I deployed my ruby api to heroku and it’s working well. Also I deployed my react app to Netlify and I can get login page. But after loginpage i can get main page for 1 second and then it’s gone. This is my first exprience with netlify and about deploying. my code is like this for login:

render() {

return (
{
this.isLoggedIn()
? <>

<Dashboard token={ this.state.token } loggedInUserId={ this.state.loggedInUserId } />
</>
: <SignIn logInUser={ this.logInUser } />
}

it means if user already loggedin get Navi and Dashboard component else get singin page. That’s why if someone try to enter my app singin page coming at first.

also i upload a video to youtube about my problem you can check it out here: https://www.youtube.com/watch?v=hgfFnNYm5YA&feature=youtu.be

and my app page:https://pensive-knuth-196490.netlify.com/

How to fix that problem?

Hi, @CihatAldanmaz, and welcome to our Netlify community site.

If you believe this issue is being caused by an error in Netlify’s hosting, please let us know. However, if the error is in the site’s custom code, then our support staff won’t be able to assist.

We don’t have bandwidth to troubleshoot custom code (unless you have a paid support contract with us that includes this level of support). However, it is possible that someone else here in community will be able to answer this question.

If you do discover evidence that Netlify’s hosting is the root cause, please let us know and we’ll be happy to troubleshoot that issue.