Hello I have a lot of problems with the groups, my group by default is "member" but each time oxide or betterchat, replace the players in default without intervention

default group tag [players]
member group tag [member] 
with oxide i add player to group member , after few hour, player automaticaly send to "default" ..

You will find it hard to remove the default group (I have removed player group sucessfully)  as it is after all the default !
If you put everyone into that group you could try this, they are still in the default group but will show Member tag in chat.

 {
    "GroupName": "default",
    "Priority": 0,
    "Title": {
      "Text": "[Member]",
      "Color": "#00ffffff",
      "Size": 17,
      "Hidden": false,
      "HiddenIfNotPrimary": false
    },
    "Username": {
      "Color": "#ffff00ff",
      "Size": 17
    },
    "Message": {
      "Color": "#ffffffff",
      "Size": 17
    },
    "Format": {
      "Chat": "{Title} {Username}: {Message}",
      "Console": "{Title} {Username}: {Message}"
    }
  },​

remember that any changes to DATA files/configs must be made with the plugin unloaded/edit/save/reload

i already try this, the problem is when put the player on other groups 'authenticated' with discord auth, after few time , the player appear with default groups and authenticated. VIP is tag [VIP] after moment this tag doesn't appear and the tag appear is [MEMBER]

[
  {
    "GroupName": "Membre",
    "Priority": 0,
    "Title": {
      "Text": "[LBF]",
      "Color": "#55AAFF",
      "Size": 15,
      "Hidden": false,
      "HiddenIfNotPrimary": false
    },
    "Username": {
      "Color": "#55AAFF",
      "Size": 15
    },
    "Message": {
      "Color": "#FFFFFF",
      "Size": 15
    },
    "Format": {
      "Chat": "{Title} {Username}: {Message}",
      "Console": "{Title} {Username}: {Message}"
    }
  },
  {
    "GroupName": "VIP",
    "Priority": 1,
    "Title": {
      "Text": "[VIP]",
      "Color": "#7CFF00",
      "Size": 15,
      "Hidden": false,
      "HiddenIfNotPrimary": true
    },
    "Username": {
      "Color": "#7CFF00",
      "Size": 15
    },
    "Message": {
      "Color": "#FFFFFF",
      "Size": 15
    },
    "Format": {
      "Chat": "{Title} {Username}: {Message}",
      "Console": "{Title} {Username}: {Message}"
    }
  },
  {
    "GroupName": "VIP+",
    "Priority": 2,
    "Title": {
      "Text": "[VIP+]",
      "Color": "#FFFF00",
      "Size": 15,
      "Hidden": false,
      "HiddenIfNotPrimary": true
    },
    "Username": {
      "Color": "#FFFF00",
      "Size": 15
    },
    "Message": {
      "Color": "#FFFFFF",
      "Size": 15
    },
    "Format": {
      "Chat": "{Title} {Username}: {Message}",
      "Console": "{Title} {Username}: {Message}"
    }
  },
  {
    "GroupName": "VIP++",
    "Priority": 3,
    "Title": {
      "Text": "[VIP++]",
      "Color": "#FF3D00",
      "Size": 15,
      "Hidden": false,
      "HiddenIfNotPrimary": true
    },
    "Username": {
      "Color": "#F5DF00",
      "Size": 15
    },
    "Message": {
      "Color": "#FFFFFF",
      "Size": 15
    },
    "Format": {
      "Chat": "{Title} {Username}: {Message}",
      "Console": "{Title} {Username}: {Message}"
    }
  },
  {
    "GroupName": "modérateur",
    "Priority": 4,
    "Title": {
      "Text": "[Modérateur]",
      "Color": "#1400FF",
      "Size": 15,
      "Hidden": false,
      "HiddenIfNotPrimary": true
    },
    "Username": {
      "Color": "#E4FF00",
      "Size": 15
    },
    "Message": {
      "Color": "#FFFFFF",
      "Size": 15
    },
    "Format": {
      "Chat": "{Title} {Username}: {Message}",
      "Console": "{Title} {Username}: {Message}"
    }
  },
  {
    "GroupName": "ADMIN",
    "Priority": 5,
    "Title": {
      "Text": "[Admin]",
      "Color": "#FF1800",
      "Size": 15,
      "Hidden": false,
      "HiddenIfNotPrimary": true
    },
    "Username": {
      "Color": "#F1FF00",
      "Size": 15
    },
    "Message": {
      "Color": "#FFFFFF",
      "Size": 15
    },
    "Format": {
      "Chat": "{Title} {Username}: {Message}",
      "Console": "{Title} {Username}: {Message}"
    }
  },
  {
    "GroupName": "default",
    "Priority": 6,
    "Title": {
      "Text": "[Non-Auth]",
      "Color": "#55AAFF",
      "Size": 15,
      "Hidden": false,
      "HiddenIfNotPrimary": false
    },
    "Username": {
      "Color": "#55AAFF",
      "Size": 15
    },
    "Message": {
      "Color": "#FFFFFF",
      "Size": 15
    },
    "Format": {
      "Chat": "{Title} {Username}: {Message}",
      "Console": "{Title} {Username}: {Message}"
    }
  }
]

try changing "hidden if not primary" to true

 "GroupName": "Membre",
    "Priority": 0,
    "Title": {
      "Text": "[LBF]",
      "Color": "#55AAFF",
      "Size": 15,
      "Hidden": false,
      "HiddenIfNotPrimary": false
    },​

i try, but same problem, all member moved to false groups ...

the order is wrong but I cant post the fix or post my discord name... priority 0 should be admin, 1 moderator. 2 VIP++, 3 VIP+ 4 VIP 5 member and 6 non auth

i directly remove groups member , for only put Default for all member. 

yeah order is wrong... Admin group is priority 0 (ownerid) and last is default ID 3-4-5-10 or whatever you have in the order. That's should be fine after that... Also you can have default as member but if you want separate members group, no problem, same for something over Admin, still possible just make admin 1 or 2 and add the group above with 1 or 0 priority, ex Owner group ; )