I have the Insider Win 11 but not on a PC with Support Assist. Probably some issue with Win 11 compatibility. Support Assist 3.10.3 is the latest version. If you don't have this, install it and see if it helps. Support for SupportAssist for Home PCs | Drivers & Downloads | Dell US
Hi   Dell Support Assist, the app, has been causing my XPS9700 to freeze when I run the diagnosis tests. I currently run the device with Windows 11 Beta, why is this happening?    
Dell Support Assist would cause whole system to crash (XPS 9700 on Windows 11)