OXO TRunk IP with OPENVPn 403 forbidden

[fennec62]

Hi

I use OXO with trunk IP, on my network I have two WAN, fiber and LTE

Trunk IP allow IP fix to connect so for fiber I have IP fix but not in LTE

So I wan't use VPS with IP fix and for that I use openvpn

I send all traffic OXO to openvpn, internet ok ping ok and I have IP fix from VPS

Trunk connect is ok

11.0.0.2 is IP VPN to Voip
X.X.X.X and voip.fr are IP and DNS Voip supplier

16:52:51.062616 IP 11.0.0.2.sip > X.X.X.X.sip: SIP: REGISTER sip:voip.fr;transport=UDP SIP/2.0
16:52:51.075515 IP X.X.X.X.sip > 11.0.0.2.sip: SIP: SIP/2.0 200 OK

But when I try to call my office I have 403

16:55:12.217852 IP fen.fr.sip > 172.16.10.246.sip: SIP: INVITE sip:321000000@172.16.10.246;transport=UDP SIP/2.0
16:55:12.231291 IP 172.16.10.246.sip > fen.fr.sip: SIP: SIP/2.0 100 Trying
16:55:12.234235 IP 172.16.10.246.sip > fen.fr.sip: SIP: SIP/2.0 403 Forbidden
16:55:12.243642 IP fen.fr.sip > 172.16.10.246.sip: SIP: ACK sip:321000000@172.16.10.246;transport=UDP SIP/2.0

I think because SIP IP from VPS and not from Voip supplier voip.fr ?

can I fix that ? thanks a lot