Hello Ariel,
Thank you for reaching out to us.
We have not found any issue at our end.
May I know if you have checked marketplace plugins with WooCommerce and standard theme (storefront/twenty). Please deactivate all your plugins, except WooCommerce and WCMp + addon. You can then check the flow. If everything is working fine, in order to detect which plugin is causing conflict- please activate each plugin consecutively and check the flow.
Similarly, for theme conflict- please deactivate the current theme and check with standard WooCommerce theme (storefront/twenty) It is suggested to please perform these tests on your staging website and keep us posted with the outcome.
If the issue still exists then kindly share the admin and vendor access (staging site) and FTP access and while sharing the access kindly mark the reply as private.