BF old office password

Hello,

I extract hash from oldoffice ppt with office2john.
The hash is like this : $oldoffice$3*xxxxxx*xxxxx*xxxx

Ok, I used this commandline for bruteforce this hash :
hashcat64.exe -a 3 -m 9800 hashppt.txt --increment --increment-min=6 --status -1 ?l?d?s?u ?1?1?1?1?1?1?1?1?1?1?1?1?1
After ~1h, in pot file I have this :

$oldoffice$3*xxxxxx*xxxxx*xxxx:yyyyy

I try to open my ppt with the pass ("yyyyyy"), but it doesn't work.
Any idea?