I am running a Flex 6400, SmartSDR 2.4.9, WSJT-X 2.01 and JTAlert 2.12.1. No additional control software loaded, although I do use HRD logbook running without the HRD control module. Lots of contacts on FT8, but I continue to have spontaneous mode changes from DIGU => USB. The net impact of this change is likely minimal, probably the last .300 khz of band pass, but I don't understand why this continues to happen. There are some much older posts regarding this, but none seem to apply to me. Is anyone else experiencing this phenomenon, or understand why the SDR mode will not stay where it is set (with no change in band) using WSJT-X?