The connector you have zip tied at the top is not one of the flywheel hall sensors. That connector is the cylinder head temperature sensor. That sensor has been superseded with a two wire sensor that uses a dedicated ground wire instead of the previous single wire grounding through the engine. Looks like your sensor is a two wire sensor but they still can be problematic. Usually it's a hot condition that affects those sensors.
The flywheel sensors are the both the same sensor but provide different functions in their respective positions. One sensor is a legitimate timing sensor that uses flywheel "teeth" to provide crankshaft angle reference to the ECU. The other sensor is a position sensor and uses a set screw in the flywheel for reference. It's my understanding that this sensor is only used for starting the engine and after startup it's function doesn't affect engine operation. Both sensors are prone to heat degradation since the wire leads are somewhat close to the exhaust heat. The wire sheathing cracks, allowing water to penetrate the internals and you get intermittant behavior. Note there's an alternative BMW part number for these sensors that's half the price of the same Porsche part, excepting a bit longer wire length on the BMW sensor.
We had a no-start issue with an '86 BMW 325e that uses a similar Motronic engine management system. The set screw in the flywheel was installed loosely and the gap was not proper. Thus the sensor couldn't detect the screw and it wouldn't start. Ironically the guy we bought it from traced the same no start problem when he bought it to a missing set screw. He "fixed" the issue with a new screw that eventually came loose again!!!
The bracket is just a fixture to hold the wires neatly. It does nothing to secure the electrical connections. The connectors themselves are responsible for proper electrical connectivity and they actually snap together very well and are often hard to disconnect.