What happened
Regression - this bug is not present in latest 5.2.3p2 and in 5.3.0a1, but present since 5.3.0b2 and in 5.4.0a5
When you use LobbyManager and ( just example)
- you set Minimum Players to 3
- you started 4 clients ( e.g. standalones)
- and then when you press "START" for 3-rd - the 4-th one will be forced to start the game even if not ready

Real life scenario : A Quake-Like, can be played at 16 players max, so your max player is 16, but you can play 1 on 1, so your min player is 2.

Before (pre 5.3) if 5 player where in the lobby, and one player was pressing ready, it had to wait for the 4 other one to get ready. Logical, every game work like that. If a 6th one connected before everybody was ready, when you had to wait for the 6 person to be ready to start the game

Right now (since 5.3.0b2), if there is 5 persons in the lobby, and 2 because they are happy of their color/loadout/whatever, click ready - the 3 other one will be dragged in game

2. How we can reproduce it using the example you attached

- please see attached video for more details
1 Open attached project and scene "scene1"
2 Build and Run standalone
3 Press Play in Editor
4 In Editor press LAN Host
5 In standalone press LAN Client
6 Press "START"-button for one of the clients
Actual result: second player will be dragged to the game as well
Expected results: the game should be started only when ALL players will press "START"