Oh my god! I fixed it!
Now check out how this obscure bug happened:
I thought "there may be a line of code that is causing this bug" so I started deleting all event groups one by one. Delete one, test, CTRL+Z to get it back in place, move to the next one
Then I deleted a group called "Tower behavior" and the bug disappeared!
Inside it I did the same thing, deleting blocks of events until I found the one event that was bugging. Take a look at it:
For some reason, at some point, construct changed this:
Into that. Its the same as if I went into each event and changed the drop down options to "Use Expression"
Why the hell this happened? I don't know. It's a weird bug that construct caused for some obscure reason, maybe when saving, I don't know.
Thanks to everyone who helped me find this bug!!