Discussed on dev-list:
Must use the public pool for callbacks as the most obvious step.
There's a reproducer project. Long story short, .Net can invoke cache operations with future callbacks, which will be invoked from striped pool. If such callbacks are to use cache operations, those will be possibly sheduled to the same stripe and cause a deadlock.
The code is very simple:
await cache.PutAsync(1, "Test");
async/await should absolutely not allow any client code to be run from stripes.