HI, I ran into the same issues but was able to make it work by pinning the versions of axon, nx and elxa to the latest 0.5.x version and make the examples work the same way as in the book
{:axon, "== 0.5.1"},
{:nx, "== 0.5.3"},
{:exla, "== 0.5.3"},
hope this helps if someone else comes across this issue