Hello Chabbils,
Sorry for misunderstanding, i guess comparison on same month prior year may be not straight forward. However, there would some tricks to achieve it.
Could you check this https://democentral.learnquicksight.online/#Dashboard-TipsAndTricks-Calculation-Year-over-Year-KPI and let us know if it helps.
May be this old post could be helpful as well -Need help to replicate Year over Year - when KPI is a calculated field - #4 by Ying_Wang
Thank you.
cheers,
Deep