Black screen and full speed fan gpu

Product: Apex Legends
Platform:PC
Please specify your platform model. PC
AMD or Nvidia Model Number Amd Vega 56 Asus strix
Enter RAM memory size in GB 16
What is your gamertag/PSN ID/EA Account name? Lemouchou
Please provide your squad mates' gamertag/PSN ID/EA Account name if possible.
Are you using any software with an overlay? No
Which Legend were you playing (if applicable)? Wraith (main)
Which Legends were your squad mates using (if applicable)?
Where did the issue occur? Returning to the lobby after a match
Which part of the map or menu were you in? If you don't remember the exact name, please describe the area or what you were trying to do in the menu. 0 issues during the game only after or before, but it seem to be king canyon every time
What were you doing when the issue occurred? E.g. respawning a squad mate at a beacon, using an ability, a squad mate left the game. Nothing
Did your squad mates also experience the issue? I don't know
How many matches had you played in a row before the issue occurred? 600 hours in apex until saison 5 appear and * up the pc
When did this happen? (dd.mm.yy hh:mm) Saison 5 lunch
How often does the bug occur? Every time (100%)
How severe is your issue? Major impacts to gameplay
What happens when the bug occurs? Black screen with full speed fan gpu. I have the only option to shutdown the pc
What should be happening instead? No crashing
Steps: How can we find the bug ourselves? I don’t know. It’s a new pc so I don’t know.

‌

i began playing apex on my Mac with an egpu and I have no big issues since saison 5 : this thing happen. So I built a new pc with my graphic card I had and black screen again. 
I try to only stay on lobby and after 1 minutes or two it crash. But when I lunch a game and I return to lobby it crash really quickly. 
i saw pc graphic crash on Trello was resolved but not for me… 

thank you for your help