As owner of RME interface my advice is to write in some place your totalmix setting. Then reinstall your RME souncard, and Totalmix will reinstall as well
Mixing with monitors is always the better choice but the monitors have to be studio monitors not pretty listenings monitors.
Mixing with headphones, also the best ones headphones, have one of the most deficiencies in listening: the lack ot true basses that is the lack of a real listening of the project.
With the latest update I find some simple operations don't go smoothly as copy and paste. I have to get out of the ptoject coming back and try copy and paste one more time and everything is all right.