I had a format JSON block with this text (making the docs on the block) and it didn’t record traces even though I told it to multiple times.
{"object":{"string1":"text","string2":"text","object_jr":{"string_mini":"more_text"}}
One of the objects wasn’t closed. I fixed that issue by adding another curly bracket to the end, and flow traces worked as they should. I got no errors when it was broken.