Thanks for all the info.

I found the problem. The board.txt and build settings were being over cached in releases prior to last few weeks. The work to separate and re-load the build settings didn't properly take into account board.txt

So if Apple Bonjour was not installed the network settings from board.txt were not applied correctly.

There is a new release available with the fix.

There are some additional minor improvements

1) Serial or Ip can be specified in board.txt: serial.port=
2) The Ip address used to upload (or attempt upload) are remembered for the duration of the current session so they will appear in the Serial Ports List and be available to selection. This makes it easier for non-bonjour users to to switch between network and USB
3) Removing board.txt properties is cleaner

Thanks 😀