Why does a surge protector that has been working fine for years suddenly start turning off by itself several times a day when everything else in the house does not lose power and is fine? And, more importantly, what can we do about it?
Surge protectors wear out over time. Each surge will reduce its effectiveness until it is pretty much is worthless. It may be that there is a MOV in it that is intermittently shorting out. I would replace it as it isn't giving you any protection at this point.