Box has released a public Beta client for Big Sur computers with the M1 chip. The beta Box Drive client requires Reduced Security mode. Box intends to release a version of the client later this year that will not require Reduced Security mode.
To access the Beta client and instructions, see: https://support.box.com/hc/en-us/articles/1500004479962-Box-Drive-support-on-devices-with-M1-chips
For assistance, contact the Service Desk.