You are trying to import a TMX in Language Cloud and some TUs are recognized as invalid and discarded although apparently they are valid TUs.

Match the values of the custom field type by either updating the TMX or the tenant with the desired type.

The reason why the TUs were discarded as invalid is because the types of some custom fields are not corresponding in the TMX with the types from the tenant.

Example:
The TMX contains TUs with the field "Order No" with the type MultipleString:

However, on your tenant, if you browse to Field Templates


the field "Order no" (the naming is not case sensitive) is set up as simple text (not Multiple):