Cubase pro12 crashing

Cubase 11 has always been rock solid- Cubase 12 crashes when left opened for too long- Steinberg support knows of the issue and says has no fix- happens with all VSTs disabled [third party VSTs are usual suspect]- any thoughts? [reverted to 11 for now]
Windows 10 pro
Intel I7 - 3.7 GHZ
48 GB Ram
64 Bit
RME Fireface 802 sound

Hi,

Could you attach the DMP file, please?