Thunderbolt issues

Hi , I have the dell xps 13 9300 laptop using ubuntu 19.10 after switching a longtime from windows to linux so I am new. I am trying to use my eGPU with the Radeon RX 580. But everytime I connect it to the laptop. my system freezes and stops responding. Nothing responds, not even the keyboard and I have to hard shutdown.
At first I thought that it was in the bios, but thunderbolt was activated.
I thought I was missing a bolt but it was already installed
but as soon as I connect, the system freezes.
So I’m so lost

Sounds like a kernel issue and I recommend reporting it:

ubuntu-bug linux

It is worth testing if the latest 20.04 daily image with its slightly later kernel has the same issue - you can write the image to a USB stick, boot into the live session and then connect the eGPU to your laptop.

You were right. After I tried as you mentioned with version 20.04 and connected the eGPU. It ran with no issues at all. So you were right. Its a kernel issue.