Pisarto review for Shopify Search & Discovery

Each filter that is based on a metafield gets its label from the metafield definition name at the time the filter is added. So, to edit the label, you need to edit the metafield definition name, remove the filter, and add it again. It seems you have completed the first step, which is to rename your metafield definition. You now need to remove the filter and add it again inside the Search & Discovery app.