On March 14, 2022 Apple released macOS Monterey (12.3). Soon after we heard about issues with FireWire. Customers reported that LifeFlix no longer detected their DV camcorders on their Mac.
In addition to LifeFlix customers reporting this, it is also documented in this forum post on MacRumors:
We hope Apple fixes this soon. They released a minor update (12.3.1) but this did not fix it yet.
In the meantime, here are some links to downgrade the OS on your Mac:
We will keep you updated.