Most of the IR cut filter assemblies I've seen are fairly fragile. They are generally magnetically operated (there are some servo based ones, but those tend to be too large and expensive). Some have a magnet at either end of a "slider", with a coil of wire around the actual glass filter, others have the magnet on the glass and the coil wound around the assembly.
The move the cut filter you apply a DC voltage one direction or the other, which creates a magnetic field in the wire, which then attracts it or repels it relative to the fixed magnets. This causes the glass piece with the IR filter coating to move back and forth.
This is a good example of the assembly:
Sometimes you have to (or, alternately MAY) apply a steady voltage to keep the fitler glass "locked" in one position or the other.
Ultimately the drive voltage and current is regulated by the camera and the commands to move the filter are issued by the camera's control logic.
Things that can go wrong:
Supply voltage or current is too high, damaging the very fine wire coil.
Supply voltage or current is too high, causing the glass assembly to move too far/too fast and get wedged
Supply voltage is too low, from bad power management in the camera or other factors, causing the coil to not be energized enough to make a strong enough magnetic field to initiate movement.
Filter is moved too frequently, causing the wire coil to break (in cases where the coil is on the moving glass, and not stationary on the assembly).
Other components around the lens assembly interfere with the magnetic field and cause the filter not to move.
Lens assembly is inserted too tight/too close to the filter assembly, causing it to bind up and prevent movement.
Camera seals are poor or internal airflow design causes dust to build up, preventing movement of the filter.
You could have 10 vendors all using the exact same component, and they could do something wrong that causes their own distinct failure mode. Given how obvious failure of the IR cut assembly is in the camera image, I've often been surprised that they are such a delicate and crappy design.