How to Solve My IAX2 problems

I use the 4 Freepbx Servers with the IAX2 protocol. I noticed 2 days ago
that I was not registered with the other 3 Servers. I used the “iax2 show
registry” command and found I was not registered with other 3 servers.I issued a reload command in asterisk in order to connect again.
My question is … If an iax2 entry is not registered, will I fail to get inbound calls? Is there any way to have * automatically detect and re-register periodically?
I noticed the same thing and rebooting isn’t necessaryily going to fix
the issue.

qualify=yes in the IAX2 configuration may help