1-to1 NAT question in Peplink B-580

Hi, Peplink guy,

For 1-to-1 NAT mapping in Peplink Balance router( NAT-mode), e.g. B-580,

Is all traffic/protocols/service/applications are not be affected, and will be forwarded ? since I found the GRE tunnel does not work after Peplink NAT.

It seems traffic after Peplink NAT has issue ( for example, GRE traffic, SSH …)

Any configuration need to be fine tuned for NAT configuration ?