Hooooray!!!!!!!! :-D
PS: I mean, this is how science works, right, one positive example is enough for a proof ;-)
PPS: And I definitely have to look closer into this issue with Godot and null values. The bottom line seems to be: do not use null, which admittedly is documented: https://www.gdquest.com/docs/guidelines/best-practices/godot-gdscript/#avoid-null-references
And now I found the issue you mentioned: https://github.com/godotengine/godot/issues/41179 Oh man, this is brutal. This explains why I could not reproduce it because I run debug but uploaded release versions. So for the next jam I will only upload debug versions to make sure that it is always the same that I see locally.