High-end microwaves keep dying

Hi All - I bought my house just under three years ago and I am going on to my FOURTH high-end over-the-range microwave since then - first was an $800 KitchenAid that was about 3 years old, then replaced with a $400 Maytag that died within the first 6 months and was replaced under warranty (repair notes said “tip of magnetron fell out and burnt wave guide”). The replacement just died after 1.5 years. They’ve all died in essentially the same way: they turn on and run, but just don’t heat. I realize this means that something is going wrong with the magnetron/diode/transformer, but the bigger question is why does this keep happening? Could it be a bigger problem with the electric? It’s a new-ish house (~25 years old) and the microwave has its own dedicated circuit/breaker. The spacing above the electric range is pretty standard (33 inches to the bottom of the cabinet, giving between 18 and 15 inches to the bottom of the microwave depending on the depth of the unit). Is it something that power surges could cause? Thinking about putting a surge protector there for the next one. Anything else I should consider?