Parallel View: background issues

Hi everyone,
I have noticed a problem in gradient background for parallel views that still persists in Rhino7: if I make a parallel view (axonometric view) in the background appears a grey bar, something like an horizon (see figure 02) which is an error. I can avoid this problem inserting a new point away from the object (fig 03) but I was wondering why there is this problem and if it could be find a solution.
Thanks for your help!