Your base strength is 8, so a -1 modifier, and you then get your +7 for the difference (+6 for 23 Strength, and +1 to compensate for the -1).
That does not seem anywhere close to correct.
Your base STR is not 8, your base STR is whatever you come out of CC with. I have no idea where this 'compensation' +1 is supposed to come from. There would be no drawbacks to having a negative attribute score if it was cancelled out by compensatory additional point or points.
He is wearing gloves that set strength to 23, on a character that naturally has strength 8 (respecced likely). The way those items work, if you have a -1 from a score of 8, but a +4 because the item sets it to 18, the game WILL display both the -1, and then the +5 that the item gives you (the +4, plus a +1 to compensate; this compensation is for display purposes only). The total bonus for the stat is +4, just as it would be if it were 18 naturally. For an item that sets to 23, and a base score of 8, the total score is +6, yes, but the UI in that particular screen will display -1 and +7.
The +16 inconsistency is, I think, from items that give +X to either all saves or to saves vs spells.
