Outgoing calls on LocalPhone using Obi202 often don't connect

I set up LocalPhone for outgoing calls on my Obi202, and some calls work fine. But many calls don't connect. I hear several rings on my end and then silence. At least one person we called, heard our call ringing her phone, and when she answered, she said nobody was there. So this could be a case of when we call and someone answers, the call disconnects.

Coincidentally, these calls that don't seem to connect get logged and we get charged for them on LocalPhone's billing system, so LP's network must be showing that the calls are connected.

When the calls don't go through using LP, and we try calling using a different VOIP service, then the call goes through fine, so the problem is definitely on LocalPhone's end or something related to how it interacts with my Obi202.

Any tips or advice would be appreciated!