Solid/Pneumatic jockey wheel

We have an Elddis Xplore fitted with a mover (ready for when we cant move it so easily) however the solid tyre jockey wheel proves a 'pain' when trying to move over gravel/soft ground. Digging in to provide an effective anhor.

The has strained the jockey post and we had a new assembly fitted at the last service in sept. The dealer fitted an Alko jockey wheel/post.

This is now showing the same problem!

I have looked to try and find a pneumatic wheel to fit the forks however thecurrent solid wheel measures  200mm diax70mm wide and the pneumatic wheels seems to be 260x80mm. I have checked under the A frame and there seems enough space for a larger wheel to fit but Im reluctant to buy a complete new jockey wheel ass'ly.

Anyone have any suggests where smaller wheel can be purchased or if a solid rubber wheel will solve the digging in problem?

Thanks.