I have had similar experiences. Eg. I had a script where a line was still being executed despite being deleted and the script saved. I could see changes I made to code and the deleted line was still there. Relogging to the admin panel helped - the "ghost" line reappeared in the editor so I could delete it forever.
Now I'm trying to add post_process script to user/register endpoint, and all of a sudden it stopped printing anything to the log. It's a bit hard to debug cause it's run in a sequence of OAuth requests so it's extremely frustrating. I add/remove simple scripts (like print("FOO")) to various endpoints to make a differential diagnosis on what's going and I'm starting to go mad. For now it seems like the whole scripting interface is not 100% reliable.