Kendas do that! Have done since they first hit the streets, and while some (usually fairly gentle) riders might get more milage, many (if not most!) don't ever get too much more! Some get worse, and there was a time (think 2014 or so!) when pretty much every tire coming out of BRP would only ever get about that sort of milage, altho there's no denying that they've generally become a little better since then!
BTW, just beware of dropping any Kenda, XPS branded Kenda, or Kenda clone tire anything more than about 2 psi below their recommended pressure, as the lightweight construction of the
tire... err, black round things that keeps the metal bits off the ground
REALLY NEED that recommended pressure to carry the load, and that's
BEFORE taking into consideration any of the numerous 'quality control failure' issues that Kenda/XPS tires are infamously renowned for!
So in your shoes, I'd be thanking my lucky stars that you caught it before it failed catastrophically, tossing that tire ASAP, and fitting a good quality 'normal' auto tire that's better suited to your particular riding needs! I'd be choosing one that was slightly narrower but with a bit talker profile, not only cos the OEM sizes are notoriously hard to find, but also to improve the ride compliance, traction, and longevity potential of the tire, saaay, a 215/60 or maybe a 205/65R15, and running it (a stronger tire, more capable of carrying a greater load) and then running it at 18psi, cos it won't need the same 28 psi or so to carry the lightweight Spyder.
If you want more, simply type 'tire' into the Search field (top right of the page), check the 'Search titles only' box, submit the search, and settle in for a few weeks of reading!
Ps: Do look for the little triangles on the sidewall/edge of the tread that mark the 'true' tread wear indicators - like many tires, Kendas not only have 'tread wear indicators' that are shown by those triangles, but they also have very similar looking 'tread stabilising blocks' in the channels of the tread. These tend to be talker than the tread wear indicators, so show up close to the surface of the tread sooner, but they generally have a series of lines across their top that the wear indicators don't; they tend to be in less of a diagonal line across the tread face when compared to the wear markers; and of course, they don't have the little raised triangle embossed on the rubber at the edge of the tread. Many have been caught out by thinking those were the tread wear markers, but they usually start getting close to the tread surface maybe as much as a couple of thousand miles sooner. So make sure those triangles are there before you panic - but personally, I'd still be tossing at least the rear Kenda, the fronts tend to last a lot longer, because they don't usually get yo work so hard! Still, most are very pleased once they experience the much better ride, handling, traction, and tire life they can get when running a better 'real' car tire at about 18 psi. Try it, and I doubt you'll choose to go back!
