I just tested the incoming calls in Android with the voip.ms sip account.
Sorry that I cannot test it using sipgate since I was asked to provide a UK telephone number when I was tring to register one.
So it was basiclly working well, just has the account naming issues which we are trying solve right now.
I think your problem might be related to the account settings.
In voip.ms accounts, the incoming sip urls must be approved in there website to receive the call (or use DID number)
Thanks for looking at this. It was failing on a Samsung GT-I9300 running /e/OS (still in beta) so I think we could say it's probably a problem with the OS rather than with Jami. I tried it on a Samsung SM-G900F running LineageOS with MicroG and it seems to be working nicely.
Thank you for your support,
If you face some other issues, you can always contact us.
About this issue on /e/ OS, we may take a look at that in future if we have enough resources since we do not quite familar with this OS. I will make it in my to list