With the latest OSX update we, unfortunately, have experienced fallouts in the audio.
This only affects external drives that are EXFAT formatted.

The symptoms have been; cutoff of recordings done in Hindenburg. The first few seconds have been missing. Other affects have been, blank space in audio exported to the EXFAT disk.

This is a known issues with EXFAT formatted diskes and MacOS Big Sur.
We are currently working on a solution to resolve the problem.

Are you experiencing this issues, then it’s advisable to format your external hardrive as:
AppleDisk Format - APFS