@AndyHornBlower Thank you ! That was a helpful link. I did manage to update my anyma phi by using the RSYNC command from the Terminal App like this
// select download folder, e.g.
cd downloads/anymaphi-macos
// copy to ANYMAPHI drive
rsync anymaphi-v1.1.0.ayo /Volumes/ANYMAPHI
The Terminal App hangs while the anyma phi updates, but that is as per release notes.
Thank you everybody for helping to solve this problem !