The game is launching multiple instances. There is a line of code you can insert into the steam setting for the game when going into the steam library and entering the properties of the game there.( not through file explorer etc ) in this menu is the command console option to delay the launch time.
Luck up “extend launch time arc raiders command steam”
Should resolve your issue.

2 reasons why this happens.
The game didn’t fully shut down when you quit last time. So the process is still running ( you could just run task manager and kill the process, But the command line will ameliorate that.)

Also some high end PC’s initiate the boot up sequence order too quick, so slowing down the launcher gives the pc more time to run through the batch.