Fossils from various epochs show the same creature in the same state. This is typical of the fossil record, and diametrically opposed to Darwin's prediction.
That seems significant to me.
"and diametrically opposed to Darwin's prediction."
Wrong.
Change does not happen for the sake of change. There has to be some pressure that reinforces/rewards some trait.
Take the cockroach. The basic idea hasn't changed since the dinosaurs --- except where something weird happens.
They are in the fossil record unchanged to date.
You have to have a pressure to change a species.
For example, to stick with cockroaches, there are deep-cave cockroaches. In that environment, REALLY long antenna are rewarded by finding more food and thus having more babies. Eyes are effectively useless. Hence, there are lots of blind cave cockroaches (a defect that would be fatal in a world with light) and lots of cockroaches with 4-5 inch long antenna --- something that would be worthless in a lighted world where you can see.
So, no, your understanding of the theory is flawed.