New to Raspbx - Trunk Outbound Calls Fail

I am new to RasPBX. My last FreePBX install was 2006 & it ran well for more than 10 years, so I know a little, but not enough.

First RasPBX install and my test call via the provided Star Communications trunk just worked. So did an IAX and SIP trunk.
I did an install of Webmin which broke the system, so again I dd copied the ISO to the SD card. Since then, I have not been able to complete a call to via a trunk.

The system is - Raspberry Pi 3 Official Desktop Starter Kit (16Gb)
Model name: ARMv7 Processor rev 4 (v7l)
CPU max MHz: 1200.0000
CPU min MHz: 600.0000
I tried from the ISO install, raw… no go.
I updated… no go.
It is now Asterisk 13.13.1
I looked at Core set debug 5 and see it is selecting and trying every trunk.
One trunk is IAX. Two SIP.
I have bypassed my home router. I have tried VPN client in the home router to avoid possible interference by my ISP.
My rebuild gave me a different result than previous attempts. I now suspect a build-hardware problem. Maybe the 8 GB SD is too slow or faulty? I have been messing for more than a week for hours a day.
Why would it work the first try, then never again? Extension to extension works no problem.
Have you any ideas? Thank you.

Here’s an alternative implementation for the Raspberry Pi:

You might give it a try and see if you get different results.

Thank you reraikes. I had already solved my outbound calling problem. It was caused by various routing-firewall-protection variables, all external to my system and not exactly under my control. One was at the VPN service my router was using. Also? My lack of experience. Inbound? Not yet. I am waiting for my ISP to properly forward from by static public IP. My friend in the USA will want to link his * system to mine, but I await hearing from my ISP. I did think that qualify=yes would deal with that anyway, but it seems not. Cheers. P.S. I did learn how to comb through - raspbx*CLI > core det debug 5. Copy and paste to gedit, then make a test call, then search for an identifying term, such as the phone number dialled. Then you can see each trunk attempt and the results. Neat. I love asterisk… but I needed a decade > brain-update.