Codec conflict

For some reason call starts as g711 but it actually encodes/decodes as g726?
Any explanation is appreciated.

Thanks,

Caller ID Name: (N/A)
DNID Digits: (N/A)
State: Up (6)
Rings: 0
NativeFormats: 0x4 (ulaw)
WriteFormat: 0x40 (slin)
ReadFormat: 0x40 (slin)
WriteTranscode: Yes
ReadTranscode: Yes
1st File Descriptor: 32