Ex-spouse still on mortgage, declared bankruptcy question

my ex and i got divorced almost two years ago. his name remained on the mortgage as i wasn't in a position financially to refinance on my own. a few months after we divorced, he declared bankruptcy. last summer, i wanted to attempt to refinance the loan to put it in my name only and the bank (bank of america) told me that it wouldn't be possible because my ex had declared bankruptcy. does anyone know why this would be the case and if the bank is giving me bad information? i've paid the mortgage on time and in full since the divorce. even still, why would they not want me to *try* to refinance and put the loan into my own name (i have not declared bankruptcy). thanks in advance.