M1 Mac Mini - usb peripherals disconnecting

Hi, I have a Behringer U-phonia UMC404 HD audio interface and an Esi M4Uex interface, connected by usb. This set up worked fine under Catalina on my iMac; with Big Sur (11.2.3) and the Mac Mini, I have to unplug and replug the usb C cables after the Mac wakes from sleep, to get the Mac to recognise these peripherals again (in Logic Pro X 10.6.1) . I also have a Time Machine back up drive connected via usb A which I cannot get to remount after the Mac dropped it. All the peripherals are powered externally. Can anyone help to remedy these issues please?