accumulator payout off?

had a weird moment with an acca payout this morning. i had a 6-leg football acca and all the results hit but when i went to check my balance, it felt lower than what the slip showed at bet placement. i’m not talking about massive odds changes or anything, just off by enough to bug me. double checked each leg and the odds all matched up, so now i’m wondering if something happens with certain markets or maybe there’s a small print rule i missed.

anyone seen this before? is it normal for payouts to change after placing the bet? or is it more likely a mistake on their side? i trust the process most times but i don’t love blindly assuming the book is always right.