ClientTravel Not Working in a Session based game

Hello!----------
I am working on project where you can pick your mech in a level then pick your planet in another level and finally create a session or join an ongoing session after which everybody travel to final game level. I am using “server travel” on every phase because my playerstate carry all the picked actors and I dont want to loose them with an “open level” command. (I use one local computer and NULL subsystem to test it)
But because I don’t understand the system fully I coudnt accomplish it. Can somebody answer these questions:

  1. Is it possible to create and start sessions on client and then on a listen server join to that session. In another words should somebody be a server to start or create a session ?
  2. Do I have to make one of the instances listen server or dedicated server or is it Ok to make them both client.
  3. My Client travel fails when it is called from a Listen server instance, why and what should i use to travel to join an ongoing session opened by a client,
  4. What do you advice me : if I use open level to travel, everything is Ok but my playerstate information(selected character selected planet etc…) is lost, if I use servertravel I cant contuniue to this project. How to you recommand me to setup this?? For example could it be another server http call to set and get the information maybe or using
    save game system or some tmap on gameinstance ?? how would you setup this ??

I am using this tutorial code :
How To Use Sessions In C++ - UE4: GuidebookClick Here
Here is my cpp file:
https://drive.google.com/file/d/1sXMQ6guC5DmM2sGxQkEXfGM8OIMf5zR9/view?usp=sharing

I prepared a small video to showcase the problem:
https://drive.google.com/file/d/1Xf68RLXmsjsWY8ALSD0cyALHI3zVQVVR/view?usp=sharing
I would be more than happy if somebody look at this and guide me to right direction please. I am really on dead end here.