Lots of noise from wheel hitting underside of arch

Ive just had 2 weekends away in the van a 2011 Elddis avante 564,ive never noticed the gap/space between the tyre and the arch,but coming back from woodhall spa on the B roads it seemed to be bottoming out and the tyre hitting the arch inside.(black plastic)

i measured it and there is only around 2" MAX gap,on the other side 2.5" to me this is not a lot of clearence.

the style of van you load where the bed is so i was assuming its lower on that side a little bit?

looking at other makes the newer vans do tend to have less space but all more then mine,the van was only loaded with a awning and clothes for a weekend.with the awning over the axel.

Ive contaced my dealer but wandered if anyone has had this problem,

thanks