Since FreePBX started using PJSIP as their default SIP stack, the port for chansip is now 5160 by default.
Port 5060 is now used by PJSIP. Which as you found out wasn't configured to the MiVO250.
That would be why your calls were failing previously.
If you want to use chansip (as a lot of online material will reference it) just change the port on the MiVO250 SIP Trunk config to use port 5160 towards the FreePBX.
