I think the numbers are just wrong here.
The Target is 15 and you ass up bonusses totalling +8 (+3 for Charisma 16, +2 for Proficiency and + 3 from Guidance I guess),
So your target displayed should not be 9, but 7 (i,e, 15 minus you bonusses).
Or am I missing something?
I don’t know the system, but perhaps some bonuses don’t stack? (Like proficiency and guidance.., whatever guidance is, that would give +3 and +3)