best alternatives for Kong toys?

my 15lb dog has had her size medium kong extreme for nearly 5 years and it's held up wonderfully until recently. I tried to order a replacement in the same size (but red since they were out of stock of the size medium extreme), but the size was way smaller than it used to be. I tried sizing up and that was way too large even after I checked measurements in advance. I don't know if they changed the sizing or if there's an error happening or what, but now I'm at a loss. I've also seen people complain about the quality changing drastically over the years, so now I'm wondering about the best affordable alternatives? I just want a sturdy stuffable toy like classic kongs. thanks in advance!