Rush is a PIG !
Like most Adobe products, Premier Rush is a system PIG. To satisfactorily utilize Rush, the user must have DOUBLE the minimum system requirements of RAM and CPU. Otherwise, Rush will simply lock up, hick-up, and misbehave in all sorts of bad ways. My Mac Mini OS Catalina 10.15.7 has 8 gig of ram and 442 gig of hard disk available, yet Rush crashes the system.
I posted a question to the user forum asking what steps I could take to optimize my Mac Mini to get Rush to behave. All of the Adobe Techs replied "Get 16 Gig of RAM and a 500 Gig SSD". I was hoping they would offer real world answers like "Shut down the following non-essential programs and background services". But nothing of the sort was offered.
So; Adobe should correct its "minimum system requirements" to reflect what is really required to run Rush.