Frequent disconnections prevent me from playing the game

After completing the story phase in the game (the story itself had no issues), I am unable to enter the Abyss. When I use a map to open a portal and enter it, after a few seconds of loading at the loading screen, it shows “An unexpected disconnection occurred” and I am returned to the login screen. I have not been able to enter the Abyss properly even once. I am certain that my internet connection and game files are not the problem. This disconnection issue is preventing me from enjoying the game normally.