Hello,
The phone in question is the YeaLink T46S. Before I learned about the BLF fields, I populated contacts to 7 of the 10 buttons as a "Custom Key". Then when I learned about the Busy Lamp Fields under "presence", I set all 10 on my dekstop application, then my phone restarted and only the last three fields populated (the ones I had not previously set as a custom key).
I cannot figure out how or why, but the original 7 will not populate.