Bed-guards for fixed bunk caravan

We're trying to find a solution for a bed guard for a boisterous, adventurous 14 month old for the bottom bunk of our fixed bunk van.

We've tried a "bought bed-guard" but the ladder gets in the way.  Last year we muddled through plugging the gap with the foam cushions from the dinette, but this year that'll be just seen as a climbing frame! A relative suggested the webbing used in boats bunks - but the only one I can find has too big holes, so he'd get tangled up in it.

Has anyone got a tried & tested solution?

Thanks