Perspective Grid - Unable to make grid adjustments

[ag45537490]

I am unable to adjust all adjustment points except for the horizon height and left and right grid planes.

But when it comes to the other adjustment points the cursor changes to a solid cube (or single arrow when I press option key) vs a two way  arrow, grid or box, as documented from helpx.adobe.com and videos I reviewed to troubleshoot this issue.

I am using the latest Adobe Illustrator running OS Catalina 10.15.4

Any help would be greatly appreciated.

[Monika Gause]

In order to move the perspective planes, grab them at the bottom:

Cursor in the screenshot is caused by the screenshot utility. It is usually the 2-arrow-cursor.