Form 1099-R Account Number Length Mismatch

TurboTax is expecting a 24 character Account number, but by 1099-R forms show account number length of 14 to 21 characters as shown in the lower left of the form.  TurboTax bounces back and asks for a 24 character account number.  I have tried padding with spaces before and after, but TurboTax will not accept that.  Suggestions on how to proceed?  Thanks.