When I add a new extension to FreePBX, the buttons sync OK but the default template doesn't pick them up.

I think I discovered the problem; I had selected "All Buttons" under groups

Work-around ... when I de-select "All Buttons", everything shows (just like the note says it should)

FreePBX 12.0.74
FOP2 Manager - Version 1.0.7
FOP2 Server Status: OK - Version: 2.00