There is this question I have read about the 3x+1 conjecture so I am thinking of 3x-1 instead closed as not research level.
It is about replacing $3n+1$ with $3n-1$ in the Collatz conjecture.
OP shows some effort done: three attracting cycles discovered, these being the only ones conjectured; I don't see any easy answer to that.
I believe this is one of the cases when the OP might remain ignorant about the closure reason. Why is this not research level? I don't know.
What to do in such cases? Should not the OP be somehow notified more clearly about the closure reason?