Pip inflation

Hi. I received enhanced daily living and standard mobility, with the new rates being 101.75 and 26.90 that is 128.65 a week x by 4 would be 514.60 but today my pip was paid at 497.74, the previous amount was 467.40, am I calculating something incorrectly as I know the math is correct but maybe I'm not understanding how pip works in terms of monthly payments adding up. I understand its still an increase which I'm grateful for but confused why it is less as even 10.1% of 467.40 would be just under 47 and 467 + 47 would be just under 514, so I've seemingly been underpaid by £17 but I don't want to call in case I'm wrong and honestly, the anxiety alone makes me not want to call as I struggle talking to these people and I'm always terrified by saying anything to them at all, they'll reassess which I know is silly but I really struggle with these calls.