In short, room_assign() has been buggy for 5+ years. I did a deeper dive and discovered that it is creating two types of instance doppelgangers, one of which persists across rooms and is "kinda" hidden from the Debugger. Both types cause errors with the original instance's variable struct, which can cause all sorts of bugs.
Description
Details in included "Bug Report Breakdown" notes.
In short, room_assign() has been buggy for 5+ years. I did a deeper dive and discovered that it is creating two types of instance doppelgangers, one of which persists across rooms and is "kinda" hidden from the Debugger. Both types cause errors with the original instance's variable struct, which can cause all sorts of bugs.
Related issue from April 2024: https://forum.gamemaker.io/index.php?threads/two-instances-have-the-same-id.104430/post-666857
This could be a very useful function if you got this bug nailed down.
Steps To Reproduce
Download project, follow instructions on-screen. Refer to "Bug Report Breakdown" notes.
Which version of GameMaker are you reporting this issue for?
IDE v2024.6.0.157 Runtime v2024.6.0.205
Which operating system(s) are you seeing the problem on?
Windows 10.0.19045.0
Which platform(s) are you seeing the problem on?
Windows
1dfed4c6-df5b-4b9f-9fc3-754bbad43a2e