The reason of the "400 Bad request" is the syntax error in your DialPlan rule.
From = sip:8900%2@ in Deploy Pattern must be a SIP-URI.
For example
From = sip:8900%2@200.139.100.200
or From = sip:8900%2@sip.xxx.com.br
or if you want to replace a username part of SIP-URI, you can write the definition like
From/user = 8900%2
NATted calls not working anymore
Moderator: Brekeke Support Team