Expertise doubles proficiency bonus, so it can’t be odd–so the +9 is both proficiency bonus (x2) and ability modifier. Since bardic inspiration is a d10 here, the characters are level 10-15, so PB is +4 or +5. It seems OP’s character only as a +1 charisma mod. Or, less likely, the character is lower level with a +3 PB and a +3 CHA mod grouping with a higher-level bard.