The inverter is designed for normal power it sounds like you have abnormally high power issues.
Adding a large whole home surge protector is about all you can do. Your inverter protects itself (by programmed values for shutdown on low voltage or from overloads).
Surges from weather events require additional protection.
Some surges are from lightning strikes , others are from switch gear changing feeds or recloser units detecting line shorts so they open and close usually 3 bumps and open to protect the lines. These bumps create massive power spikes or surges that can be dampened to values that won’t harm your electronics.
The surge protector takes the hit and absorbs the spike protecting other electronic equipment.
Since you have a known issue I would recommend a large system as the active components in a surge suppressor (MOV’s or metal oxide varistors) will fail quickly if undersized a larger system can last for years.
Basically a MOV dumps spikes over a threshold voltage to ground so your electronics don’t experience the high voltage and fail if the spikes are large the mov’s can fail but replacing a module is a lot cheaper than a 5kv inverter.