BeagleBoneBlack: u-boot to load a bare metal "kernel" why cant i use load addr 0x80000000

newbie: everywhere l look i see folks using 0x80008000 as the load Address and Entry Point
when i setup my linker and mkimage for this value of 0x80008000 … it all works
but when i try to set it tp 0x80000000 … my bare metal kernel fails to run

here is the working case

nova!> fatload mmc 0 82000000 bare-arm.80008000.v2.uimg
442 bytes read in 1 ms (431.6 KiB/s)
nova!> iminfo 82000000

## Checking Image at 82000000 ...
   Legacy image found
   Image Name:
   Created:      2023-03-14  21:20:09 UTC
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    378 Bytes = 378 Bytes
   Load Address: 80008000
   Entry Point:  80008000
   Verifying Checksum ... OK
nova!> bootm 82000000
## Booting kernel from Legacy Image at 82000000 ...
   Image Name:
   Created:      2023-03-14  21:20:09 UTC
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    378 Bytes = 378 Bytes
   Load Address: 80008000
   Entry Point:  80008000
   Verifying Checksum ... OK
   Loading Kernel Image

Starting kernel ...

bonjour tous le monde!!
ABC
bonjour tous le monde!!

and here is the failing case

nova!> fatload mmc 0 82000000 bare-arm.80000000.v4.uimg
442 bytes read in 1 ms (431.6 KiB/s)
nova!> iminfo 82000000

## Checking Image at 82000000 ...
   Legacy image found
   Image Name:
   Created:      2023-03-14  21:22:50 UTC
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    378 Bytes = 378 Bytes
   Load Address: 80000000
   Entry Point:  80000000
   Verifying Checksum ... OK
nova!> bootm
## Booting kernel from Legacy Image at 82000000 ...
   Image Name:
   Created:      2023-03-14  21:22:50 UTC
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    378 Bytes = 378 Bytes
   Load Address: 80000000
   Entry Point:  80000000
   Verifying Checksum ... OK
   Loading Kernel Image

Starting kernel ...