IPv4 transit not routed into Wireguard tunnel (IPv6 works)

[VS]

Good afternoon,

need to state I am no routing expert, so bear with me if this is a dumb 
fault on my side.

I am running bird 2.17.1 on Trixie (myASN), announcing a IPv6/48 and a 
IPv4/24 to upstream ASN via myASN. MyASN is running on a VPS which has a 
Wireguard tunnel to me here. On this side is a Pfsense with FRR 
announcing my 1.2.3.0/25 on vtnet6 (128 IPs should be here) through the 
Wireguard Tunnel to myASN.

On myASN the the IPv6 Traffic works fine. Coming in from Upstream and is 
routed into the tunnel and traffic coming through the tunnel is routed 
out to the internet.

In the case of IPv4 with stopped bird, I can ping e.g. 1.2.3.10 through 
the tunnel, which is setup using 172.16.150.8/30 using .9 and .10 on the 
tunnel ends. I also can ping the internet using the default gateway and 
the eth0 IP.

When I start bird the IPv4/24 is announced to upstream and traffic comes 
in via eth0. Also if the 1.2.3.10 host behind the Pfsense pings e.g. 
8.8.8.8, the traffic comes up to myASN through the tunnel. But the the 
package is lost, not routed out to the Internet, nor is incoming traffic 
routed into the tunnel.

I already set multihop 3 on IBGP definition because 1.2.3.0/25 is not 
directly connected to myASN and traffic needs to use the route into the 
tunnel. birdc show routes and other commands show the route are there 
and also ip route get shows the routes are in the kernel table master4 
after bird starts. No firewall active so nothing blocks any traffic on 
this level.

I am sure I am blind, but sitting since days searching for a solution. 
An link to a cool tutorial for a kinda transit traffic setup (I checked 
lots of them) or any hint for a possible problem in my setup would be 
greatly appreciated.

Thank you very much!