MasterSwapRoles and SlaveSwapRoles don't communicate

I start SlaveSwapRoles and it reports

SlaveSwapRoles Starting Data received

while I am starting MasterSwapRoles which then reports

MasterSwapRoles Starting Data Sent Message 0 Tx failed Data Sent Message 0 Tx failed Data Sent Message 0 Tx failed Data Sent Message 0 Tx failed etc.

There is no ongoing communication.

Is there another startup process? How do I get these two sketches talking to eachother?

(deleted)

Garn!
Could’ve sworn I’d attached these.
Must be getting old ::slight_smile:

MasterSwapRoles.ino (1.99 KB)

SlaveSwapRoles.ino (1.94 KB)