Vendor options on the product is not appearing.

@jeffcosta94 If you have multiple vendors, when you type any name in the vendor tab under the product, it automatically shows other vendor names in a dropdown mode.
If you visit our demo site ( https://wcmpdemos.com/addon/WCMp/wp-admin) you will be able to see that the vendors names does appear.

The issue you are facing might be due to some plugin / theme conflict. Please disable all the plugin except WooCommerce and WC Marketplace, use the default theme(twenty seventeen) and check the same. Let me know what you get so that we can assist you accordingly.

Was compatibility problem with another plugin (ebookstore), deactivating it, the wc came back to work.

thank you

problem solved

problem solved 2

@jeffcosta94 Glad to know that ??