Crash when trying to go back to lobbies while already in a lob

[jdood-is-here]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

A crash when I tried to click the button "Back to Lobbies" while already in one with the lobbies menu open

TypeError: Cannot convert undefined or null to object at Function.keys (<anonymous>) at file:///C:/Users/Jawad/AppData/Local/Temp/GDTMP--1/preview/Extensions/Multiplayer/messageManager.js:1:19657 at Array.forEach (<anonymous>) at file:///C:/Users/Jawad/AppData/Local/Temp/GDTMP--1/preview/Extensions/Multiplayer/messageManager.js:1:19412 at Array.forEach (<anonymous>) at Object.Dt [as handleHeartbeatsReceived] (file:///C:/Users/Jawad/AppData/Local/Temp/GDTMP--1/preview/Extensions/Multiplayer/messageManager.js:1:19333) at Array.<anonymous> (file:///C:/Users/Jawad/AppData/Local/Temp/GDTMP--1/preview/Extensions/Multiplayer/multiplayertools.js:1:2418) at u.renderAndStep (file:///C:/Users/Jawad/AppData/Local/Temp/GDTMP--1/preview/runtimescene.js:1:5973) at d.step (file:///C:/Users/Jawad/AppData/Local/Temp/GDTMP--1/preview/scenestack.js:1:796) at file:///C:/Users/Jawad/AppData/Local/Temp/GDTMP--1/preview/runtimegame.js:1:13906

Steps to reproduce

1. join a lobby
2. open the lobby menu using a button like this:
3. click the "<-- Back to Lobbies" button
4. 💥crash

N.B. Doesn't work every time.

GDevelop platform

Desktop

GDevelop version

5.6.277

Platform info

No response

Additional context

No response