Hash acceptance on modes 9810 an 9800

[Mem5]

Trying to crack an oldoffice $4 hash, it works with mode 9800 but not with mode 9810, any idea why ?

Code:

hashcat64.exe -m 9810 -a 3 hashlist ?b?b?b?b?b
hashcat (v4.1.0) starting...

Hashfile 'hashlist' on line 1 ($oldof...xxx): Signature unmatched
No hashes loaded.

Code:

hashcat64.exe -m 9800 -a 3 hashlist ?b?b?b?b?b
hashcat (v4.1.0) starting...

[works ok!]