According to the description, you need a class B license, not a class D. It appears that you renewed the wrong class license and probably there is a different written test for a class B. Hope you get it straightened out before you get stopped and get a ticket. Good luck.
You have probably been driving your Class A MH with the wrong class license all along and were not aware of it.
One other thing if you have Air brakes you might need "air brake" endorsement to the class B
On EDIT, disregard the above. I am wrong on this, I now believe I read the description wrong. I think you are OK with the class D because you are over 26001