I don’t know what to tell you, I just did this to my doosan mill right now and it works. It’s a 31i model b controller
Which controller do you have exactly?
I made an empty O9013 program with a bunch of eob and a m99 at the end.
Put 13 into 6053 Param
Went to mdi and put g13 and single block and it switched to program 9013