The issue is expected if the "Quality Owner" field stores string values but not Ids (numbers). In case when fields with the different data types are used as Lookup keys, the "invalid type" error occurs. Lookup key fields must be with the same data type.
Skyvia works via Zoho CRM API and is limited by its API. The names of the objects/fields and fields' data types are completely depend on the definitions of the objects in your Zoho CRM instance.
For example, there are two fields "Owner" and "Owner Name" in each Zoho CRM object. The first one stores ID values of owners (this is a number field) and the second one stores Owner names (this is string field). According to the metadata of your Zoho CRM connection the "Quality Owner" field has a string data type and, thus, stores names of the Quality owners, but not their IDs. That's why this field cannot be used in the Lookup as you have mentioned above due to the different data types.
You can check your fields data types directly in Zoho CRM.