My phone does not ring if the fax is set tel./fax answering mode and incoming call is a voice call
This is normal.
In the tel./fax answering mode, your fax machine answers the incoming call and detects if the call is a voice call or a fax call. If the call is a voice call, your fax machine will ring, your telephone will remain silent. It is recommended that you only use tel./fax answering mode if your telephone is located near the fax machine and connected to it.