$500 per month is 4.3% of your income.
That’s what your talking about saving by walking away. And you’ve been in the house less than a year.
I know it is psychologically troubling that your house is $100K underwater. It might ultimately behoove you to walk away. But you have the option of staying there as long as you want before you walk for a relatively small fraction of your salary. Maybe your next raise or two will cover the loss. Small potatoes.
I’d at least hang around for another couple years to see how far it goes and what remedies might be offered before starting to walk.
It is likely that within a few years (maybe 5 or so) that rents will be equal to your payment or higher.
But, why even worry about what your house is worth in order to save a measly 4.3% of your salary ?