When static electricity is applied to the gate during board mounting, etc., the gate oxide may be destroyed. In such cases, there is a way to protect MOSFET by inserting an ESD protection diode between the gate and source terminals. Some products adopt this measure. It absorbs a large overvoltage (surge) in a short time and works so as not to apply a voltage over a certain voltage to other semiconductor products.
Check the data sheet.
Also, as a countermeasure during the mounting process, be sure to ground the facilities and tools (test equipment, workbenches, floor mats, tools, soldering irons, etc.) to be used, and prevent static electricity from accumulating.
Personnel should wear electrostatic clothing and shoes, and be grounded with a wrist strap, etc.