We use exclusivly Grandstream GXP2170 phones and have not had any issues with them in the past. We were using a different self hosted system before moving some clients to VitalPBX. I have a location with 3 handsets. One handset works perfectly. The other 2 cannot transfer a call by pushing the transfer button and the BLF key for the extension they want to transfew to. They can transfer by pushing the transfer button and then punching in the extension number.
When they try to push the BLF key it acts like nothing was pushed.
All 3 phones are configured via provisioning and all 3 are using the same template. They are also all on the same firmware. The most recent.
Any help would be appreciated.