micropython/lora async example don't see retries

[davefes]

With a modified async def recv_coro(): as suggested in:
https://github.com/orgs/micropython/discussions/13266
ie, with a while loop messages bounce back and forth as expected.

If one unit is turned off I would expected that after 4 retries that the error message on line 161 in sender_async.py would pop-up.

What do I need to do to get the retries feature to work?

Edit ... actually none these messages as seen on the Reliable_delivery Sync version are not seen:

New output_power 10/10 (delta 0)
Sending 27 bytes
Failed, no ACK after 4 retries.

Thanks.