combinator with two wordlists and appending two digits

[b8vr]

Hi, I want to crack a password with the format of wordlist1 + wordlist2 + 2 digit number. 

I am currently trying to use this code: 
combinator wordlist1.txt wordlist2.txt ?d?d | hashcat -m 0 hash.txt

The code runs, but it keeps saying Status: Exhausted. I know this means that it couldn't find a password with the given wordlists, but I checked them both and I am pretty sure that they both don't have any words missing from them. 

I was wondering if there was a problem with my code that would cause this, or if anyone knew a different way to crack the password that would work better. Thank you in advance, I appreciate the help!

Can you use masks with combinator? I don't think you can.
If you run combinator wordlist1.txt wordlist2.txt ?d?d without piping it into hashcat, will it the output the candidates formatted per your request?