Fax initiation tones after beep after greeting message. Old ATT answering machine and new VTech.
Worked for almost two years, then two weeks ago FAX beeps started
Obi200, build 5757EX accessed through its IP address on my LAN
T38 Enable at bottom of codec profiles
Codec Profile A, T38Enable, Uncheck default, uncheck enable
Codec Profile B, T38Enable, Uncheck default, uncheck enable
Reboot - no more beeps, answering system works
Re-enabled T38 in both codec profiles, FAX beeps back. Disabled again.
Fix per Chilirock - thank you!