Hard to say. Unfortunately the only way to find out probably will be to start manually editing the OpenCPN generated GPX file. Removing the lines shown in green on your screenshot one by one and trying to import it to the Axiom. If none left, start adding the stuff shown in red to the file tot find out what it is that Axiom needs there, is Raymarine
specific and we d not produce.
Anyway, if you find out, let us know and we will see if it is feasible to resolve on our side.