So we've had at least 2 users report this - they'll die once or twice so be down to 1 life died twice but when they log back in, they'll be reset to our max of 3 lives. it resolved itself with one player after a server restart but then it happened with someone else. Testing killing them proves its an actual issue with the counter being reset and not just a visual bug on our tab menu.
Version - 3.4.0
Java 1.20.1 Pufferfish