first open Task Manager.
You will get a window like this and you have to click on Performance and then click Open Resource Monitor.After that something like this will show up and you have to find GTA5.exe, you have to right click on it and then click Suspend Process. you want to wait around 7-10 seconds, after that you right click on it and then click Resume Process.
(Note that 7-10 seconds is a estimated time range that has always worked for me. If you go back to the game and there is people still in the lobby you might want to wait a little longer however waiting too long like 15 seconds might get you kicked from the lobby so beware)
IF the first step not work try this step👇
Remove internet cable from pc and wait 3-8 seconds and then everyone will left the session
Thanks for reading my guide and hope this guide helps you,good luck in game and have a great time.