What could cause my Mac (2017 15" MBP, Big Sur) to suddenly delete all of its Network Interfaces, but they all come back after a restart?

[wiffle]

Very puzzling issue over the last month or so.... something is triggering the complete deletion/inactivation of all my Network Interfaces - and I just can't seem to figure out what it is. When this happens, the Network preference pane is completely empty and my existing interfaces are all deleted (WiFi, LittleSnitch, Usb controls, Bluetooth PAN, Thunderbolt Bridge). This is subsequently followed by essentially an OS Freeze (rainbow-wheels on all apps, most apps will become non responsive ), and the only way to fix is to hard restart the computer (by physically holding the power button).

Computer works as normal upon restart.

Seems like this issue happens more when the network is in high demand (ie. big downloads, encoding on Plex etc), but otherwise the computer runs relatively stable.

Any thoughts?

Software list:

• LittleSnitch
• Private Internet Access
• MalwareBytes
• Various Cloud portals (OneDrive, Google Drive, Dropbox, MEGA)
• Plex Media Server
• qBitTorrent / Transmission

Was essentially stable prior to about a month ago, but can't really figure out what might have triggered the change. In the last couple days, the issue has been occurring when transcoding from my MBP (Plex media service) to my FireTV 4K.