You use a Type-C cable instead of a USB bridge to connect the SSD, after startup, check the working status whether the crash problem still occurs.
If you have a multimeter, after you start the Pironman, measure the output voltage of 5V and GND of GPIO.
I hope you can provide us with a video of the problem so that we can analyze and solve the problem.
If the problem is caused by hardware, we will arrange to send you the corresponding hardware module.
So you currently have the SSD connection working properly after updating the firmware for the pi 4 right.
If not, try working with a Type-C cable instead of a USB bridge and see how the SSD connection works then.