As stated in the headline. I have configured an sip account in the system settings. Incoming calls work flawlessly. Bit I cannot call out with this sip account. Even when I select my SIP account in the pulldown menue of the dialer all autgoing calls work per SIM card.
What I do wrong here?
I will also be curious if anyone here has an answer. I was never able to get SIP calling (incoming or outgoing) working at all, so you got further than me 
Yes, incoming works flawlessly from my SIP account. Rings, colud be answered and the sound quality is perfect. But no outgoing 
I’m wrestling with this right now also. I’ve got SMS working fine using JMP, and I have successfully had a call ring at my end, and called someone on the far end, but no sound has passed in either direction.
Did you check the mic killswitch? 
I did! And my far end correspondent doesn’t have one.