Like Apple's equivalent, Google requires subscription terms (price, length, renewal) be clearly disclosed before purchase, and digital subscription content must go through Google Play Billing.
Common cause is a subscription flow that under-discloses the auto-renewal terms, or a digital-goods subscription that bypasses Play Billing for an external payment link.
"Your app offers a subscription without clearly disclosing the price, billing frequency, and cancellation terms before purchase, per the Subscriptions policy."