When following the lesson on mix I get left with an iex session I can't type anything into except [Return] and [Ctrl]+[C].

Repro:

> mix new example
...
> cd example
> iex -S mix

IEx opens but I can't type anything. I'm assuming I should be able to type and run Example.hello(), but the only thing I can do is to type [Return] (once) or exit with [Ctrl]+[C].

When I run iex -S mix run --no-start it works as expected. Maybe the lesson is outdated and needs to be corrected?

> iex -v
IEx 1.16.3 (compiled with Erlang/OTP 26)
> mix -v
Erlang/OTP 26 [erts-14.2.5] [source] [64-bit] [smp:32:32] [ds:32:32:10] [async-threads:1] [jit:ns]

Mix 1.16.3 (compiled with Erlang/OTP 26)

Update

Ok this somehow seems to be connected to the _build folder. Sometimes I'm able to use iex -S mix normally once, but only iex -S mix run --no-start works the second time. Sometimes even that won't work. And sometimes it helps to delete _build first. But I can't reproduce this consistently. I'm just super confused.