Nat /pcp / upnp with Cg-Nat

My carrier is Cg-Nat and supports PCP so I am told.
The problem I have is Mini Upnpd wont run as it detects the upstream network as a local address and shuts down.

How do I force it to run with a local upstream address and is there a way for upnp requests to send upstream PCP requests to my carriers NAT?

The isp uses their own huawei based 4g tag locked router that you are forced to use.

I have worked around that and managed to get an openwrt router to cconnect.
The isp's router must have their own implementation of upnp/ nat/pmp or something as port forwarding seens to work even with CG-Nat connection with a local address on the factory router as cvonfirmed with my xbox port tests but not so with my openwrt router.

How do I get pcp to work in my case?

Try to find something in Miniupnp doce