Hello, Welcome to BI forums! If there is anything we can look at it would be your RPT, so i suggest getting ingame with your mods and reproduce the issue. RPT might help identify an issue but cant say for sure, least we can do is look. So do that, make sure you start the game with full logs on, so in the Arma 3 Launcher go to parameters and set this setting: [ ] no logs make sure that box is unchecked. Once your done ingame then go here -----> C:\Users\usrname\AppData\Local\Arma 3   There you'll see a text document that ends in .rpt, open that with notepad, copy it all and then paste it here ----> https://justpaste.it/ publish it and share the link, from there i and whomever else if interested can take a look and maybe it will reveal something that your not seeing.   Outside that, about the only things that comes to mind is gpu temps but then that would effect the rest of the game too and not just the menus, possible it could be the gpu driver, could be something with win 11.     Ya its odd my specs are way lower then yours and the game runs fine, so ya it is odd. @Tankbuster any ideas here?

Problem is that I have no HC but I observe what is reason of this situations - dummies units prepared for players JOIN to them, blocked AI units are connected to them and dedicated still see them as players (why ??). This problem happen when players unconnect from server unexpected and dedicated not allow to change their locality ot any other client.

Using setgroupowner not work too - anyway using this command on new unit joined to group of player  (client) have no sense, beacouse join group should chenge locality of this new unit in moment of join (player's group) isn't it? I think my problem and not only mine regards to some strange non player AI units, ready for JIP and seen by dedicated as players anyway - the AI units in those goups are immortal and undelatable from console or zeus, and of course blocked form locality change.

The problem is on interpretation of dedicated some AI units ready to join players on them - when players unconnect unexpected those units are seen by dedicated server as dummy players and all AI unist connected to them before player unconnect are blocked from all those commands (this#0) is just from add action form (as you can se below), before this is used join group ets here is whole command for join AI man unit and vehicle with AI units inside (example below it work in most cases perfectly just after unconnect players it stuck) and all those AI seems to be remote forever and all setowner and setowner group commands return false.   //unit join                     private _idact_next = _x addAction ["<t color='#FFFF00'>" + localize "STR_JOIN_TO_GROUP" + "</t>",{[(_this#0)] join group (_this#1);[(_this#0),clientowner] remoteexeccall ["setOwner",2,false];dostop (_this#0);if (!(captive (_this#0)) && (((_this#0) getvariable ['SIDE',CIVILIAN]) != game_side_enemy)) then {(_this#0) enableAI 'all';[(_this#0), ([(_this#1)] call BIS_fnc_getUnitInsignia)] call BIS_fnc_setUnitInsignia}else {[(_this#0),remote_call_prisonner] remoteexeccall ['spawn',2];if (lifeState (_this#0) != "INCAPACITATED") then {(_this#0) enableAI "ANIM";(_this#0) enableAI "MOVE";dostop (_this#0);[(_this#0),"AmovPercMstpSsurWnonDnon_AmovPercMstpSnonWnonDnon"] remoteexeccall ["switchMove"]}};(_this#0) call AI_group_change},nil,-850,true,true,"","(vehicle player == player) && (side _target != sideEnemy) && (lifeState _target != 'INCAPACITATED') && (((_target getvariable ['SIDE',CIVILIAN]) != game_side_enemy) || (captive _target)) && (group _target != group player) && (alive _target) && !(_target getvariable ['CAPTURED',false]) && !(isplayer _target)",_actionmanrange];
                    _x setvariable ["action_JOIN",_idact_next,false];   //vehicle join                       private _idact_next = _x addAction ["<t color='#FFFF00'>" + localize "STR_CAPTUREVEH" + "</t>",{(_this#0) lock 0;[(_this#0),clientowner] remoteexeccall ["setOwner",2,false];{if (!(isplayer _x) && (!(_x getVariable ['GRP_CHANGE', false]) || !(isplayer leader _x)) && (alive _x)) then {[_x] join (group (_this#1));[_x,clientowner] remoteexeccall ["setOwner",2,false];[_x, ([(_this#1)] call BIS_fnc_getUnitInsignia)] call BIS_fnc_setUnitInsignia;[[_x],AI_group_change] REMOTEEXECcall ["call",[0,-2] select isDedicated,true];_x enableAI 'all'}} foreach (crew (_this#0))},nil,-850,true,true,"","(vehicle player == player) && (side _target != sideEnemy) && (group _target != group player) && (alive _target) && ({!(isplayer _x) && (!(_x getVariable ['GRP_CHANGE', false]) || !(isplayer leader _x)) && (alive _x) && !(_x in (units group player))} count (crew _target) > 0)",10];
                    _x setvariable ["action_JOINVEH",_idact_next,false];   if setowner is not for that what is? (setowner group not work in some cases so good (even if this warning message is shown about setownergroup)), anyway problem is on other thing (unconnected player's units). So question still active what are circumstances for block AI units from change their locality on dedicated - and return false?

Yes