A dispute occurs when one of your donors questions their donation with their bank or credit card company. Banks usually ask customers for a reason for the dispute. Donor complaint reasons can vary from not receiving store items to forgetting they've made the donation in the first place.
Following the donor's complaint, most banks tend to immediately side with the donor without additional investigation, and initiate a formal dispute. Stripe has a tool to help handle disputes, and in many cases you can prove that the donation was valid.
Read Stripe’s article to learn more about how to handle chargebacks and disputes here.