lh does not work

[LordOfMice]

command.com (v7.10) "lh" internal command does not work.

ms-dos player (ia32-x64):
First DOS Memory Control Block: 0206h
First UMB Segment: C000h
...
0B39 A4C6 M 0000 Block Free
AFFF ---- End Of List ---

-------- UMB N 1 -------- Linked to Conventional Memory
AFFF 1001 M 0008 SC System Program, Linkage Block
C000 0001 M 0008 System Unknown
C001 021B M C002 COMMAND Program
C21C 00B7 M C002 COMMAND Environment
C2D3 352D Z 0000 Block Free
F800 -- End Of DOS RAM --

Memory Allocation Strategy: 128 (Upper First Then Low, First Fit From Start)
UMB Chain Linked To Conventional: TRUE
Saved User Allocation Strategy: 0 (Low First Then Upper, First Fit From Start)

I.e. UMB link to main memory is established. but does not work

The real ms-dos 7.10 picture to compare:

First DOS Memory Control Block: 020Dh
First UMB Segment: 9DFFh
...
0358 9AA7 M 0000 Block Free
9DFF ---- End Of List ---

-------- UMB N 1 -------- Linked to Conventional Memory
9DFF 3102 M 0008 SC System Program, Linkage Block
...
D8F3 000F M D903 CONFINFO Environment C:\EXE\CONFINFO.EXE
D902 0690 M D903 CONFINFO Program
DF92 006E Z 0000 Block Free
E000 -- End Of DOS RAM --

Memory Allocation Strategy: 128 (Upper First Then Low, First Fit From Start)
UMB Chain Linked To Conventional: TRUE
Start Allocation Segment: 9DFFh