I am growing Cherokee Purple tomatoes from seed, and am getting black patches as well as sunken fruit. What is causing this and can it be stopped?

Do you rotate your crops?

Yes. Every growing season.

Could be due to blight?

Could be blight, I guess, but I think it may be something much worse.

I see green shoulders and cracking in the first photo combined with possible overripeness, as if the green fooled you into thinking it wasn't ripe and you left it on the vine too long.
https://www.thespruce.com/why-....

The second looks like a bad case of cat facing.
https://www.tomatobible.com/to...

I've grown this variety for years and this photo shows what the tomato looks like when it is ripe.
No cracking, not overripe, no cat facing and I wasn't fooled by the green shoulders. That's the way
it grows. The photo shows what this variety looks like when it's ripe.