CAP Java: all CQN queries for Remote Service return the same response

Hi experts. I've run into an odd error. I'm wondering if anyone has experienced this and knows how to resolve it.

I have a CAP Java application that connects to an on premise system using an oData V2 service.

I am able to send queries and get data back, but no matter what the query is, I always get the same response: it reads every single entity from the target table. For example, the following two queries provide an identical result:

CqnSelect maxEbelnQueryCloud = Select.from(PURCHASE_ORDER_SET);

CqnSelect maxEbelnQueryOnPrem = Select.from(PURCHASE_ORDER_SET).columns(c -> CQL.max(c.EBELN()).as("max"));

Could anyone provide any suggestions about what could be causing this?