The fuser is not hot enough. Try raising the temp If you have settings that is higher than what you are using. OKI printer has Ultra Heavy media weight and Card stock media type setting that I use if the toner does not fuse on the transfer paper.
Check your user manual for the highest setting that you can use so that the fuser will be hot enough for Laser 1. Also run 10 sheets of blank paper by printing a file that has a space character. That way you don't waste toner. It will preheat the fuser.
Check your user manual for the highest setting that you can use so that the fuser will be hot enough for Laser 1. Also run 10 sheets of blank paper by printing a file that has a space character. That way you don't waste toner. It will preheat the fuser.