GBX20, provisioned BLF List shows only the extension number


We have GXP2170s with GXP2200EXT. The extension board buttons are used as BLFs and they get provisioned from the UCM via the Event List URI. They display the first and last name of the extensions and they work fine.
We are experimenting with a few GXV3350s with GBX20 attached and they work fine as well, except that the extension boards only show the extension numbers, not the first and last name. They work well so far, but is an inconvenience to have to look up a list outside the phone to know who belongs to what extension. is there a setting that I am missing?


Per Grandstream’s excellent tech support, the below screenshot shows what I had missed in my setup. I hope this may help someone with the same problem.