Dealing with defeated foes is something that probably is going to vary from culture to culture. That doesn't mean it's not an open question.
Let's assume people aren't in a position to exploit the soldiers immortality flaws assuming they're known.
Ideas(Not mutually exclusive, people may mix and match):
1. The losing side is mission killed. Everyone who hasnt disconnected gets injuries that take days or weeks to heal. Dismemberment, decapitation, total body incineration, etc.
2. The losing side disconnects from war.
3. The losing side is taken prisoner… somehow. Unsure how practical that is.
4. The losing side yields their gear to the winners.
5. The losing side is red spaced. Unsure how practical that is.
6. The losing side commits mass suicide to avoid being red spaced or otherwise being imprisoned and tortured.
7. The losing side is trapped in a wide area time loop or other such incapacitating environment.