ok if mask is defined on cli but not if in mask.hcmask

Hello

how it comes that if the NTLM-hast and the Mask are defined like the following in the CLI, Hashcat does
find the password,

$ hashcat -m 1000 -a 3 dell-ntlm-hash.txt ?d?d?d?d


but no so if the Hash and Mask are stored in files ?


─$ hashcat -m 1000 dell-ntlm-hash.txt dell-mask.hcmask
hashcat (v6.2.5) starting

Error message:
"The wordlist or mask that you are using is too small"


Thank's in advance for any feedback!

Joe