[Freeswitch-users] FAX tone is not detected - sometimes

Hello, I have this line in my dial plan: <action application="set" data="execute_on_answer=spandsp_start_fax_detect transfer 'FAX_DETECTED XML default' 10"/> However, the fax is not detected at times. There is one particular fax machine that freeswitch never detects the fax tone. When I listen to the pcap, I do hear the fax tone. Is there anything I can do to improve the fax tone detection? Thanks, Ali Pey